Aquitaine (audio story)

 was the two hundred and ninth story in Big Finish's monthly range. It was written by Simon Barnard and featured Peter Davison as the Fifth Doctor, Janet Fielding as Tegan and Sarah Sutton as Nyssa.

Publisher's summary
Today should be much like every other day for Hargreaves, the computer consciousness that co-ordinates daily life aboard the spaceship Aquitaine, stationed on the outer fringes of a black hole. Water the plants, run the diagnostics, cook the Captain's breakfast; then tidy the plates away, rotate the ship, clean the windows of the observation deck. When at last the day's work is done, Hargreaves will dim the lights in the sleeping quarters. But no-one will sleep aboard the Aquitaine tonight. Because the Aquitaine's crew is missing.

But today will be different. Today, a space/time ship called the TARDIS will materialise in the botanical section, bringing the Doctor, Nyssa and Tegan aboard the Aquitaine. Together, they'll seek to discover the truth of what happened to Hargreaves' crew...

... if only the ghosts will let them.

Part one
Hargreaves narrates his daily tasks aboard the ship to himself.

The Doctor, Nyssa and Tegan hear a loud distress signal coming through the TARDIS console. They lock on and travel to the source. They arrive and step outside, only to be greeted by a Hargreaves, the ship's computer and valet, in the form of a robot.

Tegan wonders off, and looks outside the ship's large windows. She sees a black hole near-by which frightens her but Hargreaves explains that they are orbiting it. After the momentary distraction, the Doctor asks Hargreaves why he launched the distress signal and Hargreaves reveals that a little while ago his crew just disappeared. They hear a scream but Hargreaves tells them to ignore it as it is an ephemeral echo, so least he claims. They go to investigate anyway while he prepares tea for them.

They arrive at the source of the noise in the botanical garden section of the ship but they meet Hargreaves again and it turns out Hargreaves is the ship's central computer and simply takes over the robot body closest to the person requesting service, in this case the robot gardener's body. They ask him about the noise and he assures them that they are corporeal, not real. They look around and ask him about the plant life, as it seems to be growing at an unrealistically unheard of rate. The Doctor and Tegan go to find something else but Nyssa notices writing on the plants. Tegan and the Doctor are off discussing the origins of the ship when they hear Nyssa scream. They run back and find she has been injured by a plant she was trying to inspect. The Doctor worries about poison and infection and Hargreaves directs Nyssa to the medical bay to get the injury inspected and mended while they hear another scream and the Doctor and Tegan go back to investigate.

The Doctor and Tegan find nothing but they still wonder why there is no one aboard the ship. Nyssa arrives in the medical bay and Hargreaves as the medical robot begins to treat her when suddenly she feels a ripple running through the ship while Tegan and the Doctor feel it too. They hear a voice and think they see a woman running away. They make chase but can't find her. Tegan then sees it again and they trying following her again, finally cornering their "ghost". Before they can catch up, Hargreaves notifies the Doctor over the system speakers that Nyssa has "disappeared". Nyssa awakens somewhere but cannot find Hargreaves. Hargreaves, Tegan and the Doctor discuss what could have happened and decide to retrace steps. Nyssa finds the Hargreaves as the gardener robot but it does not remember her from before. She explains her predicament and it explains that she can use the intercom to contact her friends. She does, and they decide to meet up in the garden but when they do she is not there contrary to her claims. Suddenly, the ship shakes and the power fades causing Hargreaves to shut down. Nyssa, meanwhile, simultaneously feels the shake, and loses all communication with the Doctor. She is found by Hargreaves who again does not recognize her. She argues with him and asks what happened but he claims that nothing she says is true. Suddenly, Nyssa becomes frightened as she is approached by a strange figure...

Part two
Hagreaves narrates his day and then reintroduces himself to the Doctor and Tegan, who inform Hargreaves they already know him. The figure who approaches Nyssa takes off the helmet of his environmental hazard suit and introduces himself as Dr. Sergei Akunin. He asks if she is part of the rescue team to which denies. She explains what had happened and shows him her injury, so he says they will go back to his lab so he can have a better look at it and treat it (Dr. Akunin is a botanist by training who has taught himself medicine), after which they will try and find her companions. Tegan and the Doctor discuss with Hargreaves what to do next, but they are confused as he earlier claimed before the shaking that there was a life-sign which they thought was Nyssa, however, Hargreaves claims he has no recollection of this. Hargreaves prints a list of last known locations of crew members at the Doctor's behest, hoping to visit and see if they can deduce some pattern that may help them find Nyssa. They decide to split up.

Nyssa and Dr. Akunin go back to his lab where he explains he has healed his ship mates but suddenly Nyssa's legs begin to feel numb. The Doctor and Hargreaves discuss the crew and the Doctor wonders why the ghost they had seen earlier, revealed by a name-tag to be Lieutenant Freya Jennings, was in pain. Hargreaves mentions that an ergostorm like the one from earlier damaged the ship causing the crewmembers to get injured and go into statsis. Nyssa is taken to the lab and sedated by Dr. Akunin who reveals there is no actual cure and Nyssa falls unconscious. Tegan, who sighted Jenning's ghost again and decided to follow it, informs the Doctor over the intercom what Jennings' ghost is up to but ends up in a dangerous part of the ship. The Doctor warns her to return but she ignores this and pursues the ghost. Nyssa awakens and asks Hargreaves to release her from the restraints but Hargreaves can only do so under Dr. Akunin's orders as he is currently highest ranking officer present aboard the ship. Nyssa, in a feat of immense strength, lets herself out and convinces Hargreaves to help her. The Doctor realizes that the crew is further forward in time than they currently are and informs Hargreaves that he cannot remember because each time an ergo storm occurs he reboots but to the earliest point he can reboot from, which was seven days right before the first ergo storm hit. However due to the mass growth of the plants and the damage to the ship, Hargreaves has been continually rebooting from this same point in a loop for many years.

The Doctor discovers the ship has been orbiting the black hole for fifty years by checking Hargreaves' reboot logs. Just then Tegan realizes the moss is growing on her and the Doctor tells her not to move as it's making it worse, likening it to quicksand. He asks Hargreaves to do something but Hargreaves cannot so the Doctor sets off to rescue her himself. Nyssa tries to escape Dr. Akunin with Hargreaves's help. She hides from him but he continues to look for her. He explains out loud that her fate was sealed the moment she touched the plant. He explains he saw it happen to his crew-mates and that he is just trying to help, albeit in a menacing way. Nyssa escapes the room that he had trapped her in. Tegan, still stuck in the parasitic moss, is approached by a strange creature and she alerts the Doctor over the intercom. Nyssa arrives at one end of the ship, which turns out to be a dead end and has nowhere to escape to and is cornered by Dr. Akunin when suddenly there is a loud noise and another ripple passes through the ship.

The Doctor tries to calm Tegan as the creature draws nearer to her but they all feel another ergo storm coming. It passes and he manages to get to Tegan's location but she is gone. He then checks for the TARDIS since she was near it but that has disappeared as well. Nyssa awakens after the ergo storm and is greeted by a rebooted Hargreaves who does not know her. She notices that Dr. Akunin has disappeared. Hargreaves explains that there is another life-form aboard the ship to Nyssa and reveals it is Captain Anna Maynard (the storm has transported Nyssa to an even earlier time). The Doctor catches Hargreaves up after he reboots again and explains that the black hole outside is collapsing and pulling the ship closer to the event horizon. He calculates that the ship will be destroyed in less than two hours...

Part three
Tegan awakens and asks Hargreaves where everyone is but Hargreaves explains there are no other life forms aboard except her. She also notices the TARDIS is gone. Hargreaves brings Nyssa to see Captain Maynard. She orders him to take her out of sleep-stasis. The Doctor has Hargreaves give him readings of life-forms and he deduces that they seem to be further forward or backward in time almost as if Tegan was in two places at once. The Doctor notes that whenever Nyssa replied she always seemed a few seconds farther back but this means she is much farther back in time, something he deduces according to "Delahay's Inverse Cube Law". The Doctor decides they need to go back in time to save her and reckons he needs to test a theory, despite Hargreaves' confusion. Tegan is encountered by a crew member who helps scrape the moss off her and explains that she must be displaced in time by the time storm caused by the ergo storm. Lieutenant Maurizio Savinio, as he introduces himself, explains what had happened to all the crew members and that he knows what's happening because of the time storms.

Nyssa talks with Captain Maynard. She doesn't believe Nyssa, thinking she is accusing Dr. Akunin without any proof and places her under arrest. The Doctor and Hargreaves find writing on one of the walls but cannot translate it. They try retrace some patterns. Just then they are found by a confused Dr. Akunin. Savinio explains to Tegan that Jennings was infected by one of the plants and while she seemed fine at first, in fact, even stronger, she degraded mentally and Dr. Akunin could not find a cure. Tegan worries for Nyssa. The Doctor helps Dr. Akunin recover and he reveals he met Nyssa but apologizes because she was infected and will likely be dead and there was nothing he could do. Nyssa brings Captain Maynard to the place she escaped from but the Captain is surprised at how easily Nyssa broke free of the restraints, realizing she has become extremely strong and believes her to be working with one of the competitors, Henrickson Biotech. Nyssa tries to convince her she is not and eventually they stumble into the plant garden and find Dr. Akunin's work out in the open, including a jar with a human hand in it, labelled "Jennings", much to their horror. The Doctor shows Dr. Akunin where Tegan disappeared but they hear a violent shudder and the Doctor realizes what's coming. Tegan and Savinio head to a safe area, and he claims that her friends are dead. They come across the creature that was about to attack Tegan earlier. Maynard and Nyssa discuss and Hargreaves reveals that it has only been seven days since reboot but Nyssa realizes with how long the expeiremnts have been going on, this is impossible and it must be much, much longer, and realises that Dr. Akunin put Captain Maynard to sleep as a back-up test subject since she was also hurt by the plant fern sample they took from Ventrius III. They see that the sample has spread over the Captain's leg. The Doctor discusses his plan with Hargreaves and Dr. Akunin and explains that they need to steer the ship into the black hole to speed up time and find the TARDIS. Dr. Akunin believes the Doctor is a danger to the themselves and the ship and has Hargreaves place him under arrest. Tegan and Savinio try to find a way around the creature and get to maintenance but they get into a spat as Tegan realizes that she's just a replacement for Jennings to Savinio and the creature injures Savinio. Hargreaves shows Tegan where a hidden carbon dioxide extinguisher is hidden and she uses it to repel the creature. Dr. Akunin explains to the Doctor that he will not let him destroy the ship because it would be genocide and he would end up killing an entire species. Originally the crew had brought back plant samples from Ventrius III but found that these plants do not produce seeds and would likely die out. This plant life instead requires another organism in order to feed off them, in a parasitic way. Dr. Akunin surmised that he could infect his fellow crew members but put them in stasis to keep them alive but also allow the plant to grow, which he had already done with Captain Maynard and Jennings, believing he has created a new species and proudly proclaims his scientific exploit as a crowning achievement, to the Doctor's disgust.

Tegan and Savinio argue about where to go but realize they are not going anywhere in the elevator and Hargreaves reveals that they do not have the authority to use to the elevator. Savinio collapses in pain and Tegan tries to use his eyes for a retinal scan but is not recognized as he is beginning to transform. Meanwhile, outside, a second creature attempts to get into the elevator to attack them. Nyssa tries to help Captain Maynard but she demands that she leave her as she can feel herself slipping into a bestial mental state, wanting to attack Nyssa. Nyssa obeys and runs. Dr. Akunin calls his creations Akunites and is about to use Hargreaves to permanently dispose of the Doctor when the Doctor invokes the first law of robotics, reminding Hargreaves that a robot cannot harm a human. Hargreaves deems Dr. Akunin unfit for service and relieves him of it. The Doctor then orders Hargreaves to steer the ship into the black hole, hoping to tear the time fracture wide open...

Part four
The time fracture opens and past and future crash with the present. Tegan and Savinio experience another time storm and Savinio believes "the Doctor fellow" that Tegan had so much faith in is not coming. Unable to hold off the plant from fully killing him, he dies. The Doctor takes Hargreaves in the form of his head with him through the newly created hole in space-time, leaving Dr. Akunin in their wake. They arrive in Tegan's time zone and with the help of this time zone's Hargreaves, try to locate her. Nyssa, with the infection getting worse and spreading, demands Hargreaves amputate her arm. The Doctor finds Tegan but she reveals that the TARDIS is not with her and he realizes the fail-safe time anomaly relocation distributors had kicked in, explaining that they need to wait for it to arrive but there's other things they need to do in the meantime such as find a cure for Nyssa, so they set off to the garden. Nyssa realizes at the behest of Hargreaves that she can place herself in suspension to slow down the spread of infection. Tegan, Hargreaves and the Doctor are found by Dr. Akunin having gone through the hole himself and who plans to kill them but they are then discovered by an Akunite. This Akunite turns out to be the remains of Jennings and it attacks and kills Dr. Akunin as retribution for what he did to her/it while Tegan and the Doctor barely escape. Nyssa finds the transformed Captain Maynard (in Akunite form) who prepares to kill her but Nyssa orders Hargreaves to use weed killer on it, apologizes and runs off. The Doctor and Tegan feel a massive pulse from the storms occurring in the present and sending shock-waves through time. Just then, the TARDIS arrives and Tegan, Hargreaves and the Doctor get inside. He explains that Nyssa's time track will be extremely hard to find as she's been thrown back and forth and is probably several decades behind. Hargreaves suggests that they go back and put a system restore in his central processors which have not moved from their original location in the ship since the start of the mission, at every instance since the ship's arrival. The Doctor realizes Hargreaves' constant and the genius of his plan and they get to work. The plan involves going back to the start of the event and putting the crew into stasis so that they can awaken them in the present time, and Hargreaves must also send out a distress signal so the Doctor and co arrive to start the chain of events. However, the Doctor realises that by aborting the timeline they will lose Nyssa...unless, and he runs to the stasis chambers to confirm his suspicions. Before stasis, Nyssa realizes she can leave small messages on the wall with the weed killer for the Doctor but she has extremely limited time as the infection begins to take over. The Doctor in the present time finds the scrambled messages and manages to figure out that they read "Sleeping Bay Five". Nyssa, with the infection spreading, puts herself in stasis there, hoping to be found. The pod opens and Nyssa looks outside to see none other than the Doctor and Tegan standing outside and with events re-set she is no longer infected. Relieved to have found her, they head back to the TARDIS while Hargreaves completes his plans.

The crew of the Aquitaine are preparing to return home after collecting plant samples from Vetrius III. Hargreaves tells them there has been a hull breach and that they must go into stasis. They do and Hargreaves waits with them for fifty three years. The stasis pods are opened and the crew finds the Doctor, Tegan and Nyssa who get them on the TARDIS and helps them escape as the Aquitaine is sucked into the black hole and destroyed. Inside the TARDIS, Hargreaves is unplugged from the controls and expresses feeling peculiar after having experienced his "death". Tegan wishes they could keep Hargreaves with them, believing it would be nice for the Doctor to have a personal attendant although the Doctor isn't fond of the idea. However, the crew explain that they will be taking Hargreaves as he is the only proof they have of the disaster that has occurred today. Additionally, the Doctor says that he's not sure he could drink that much tea.

Cast

 * The Doctor - Peter Davison
 * Nyssa - Sarah Sutton
 * Tegan - Janet Fielding
 * Hargreaves - Matthew Cottle
 * Dr Sergei Akunin - Harry Myers
 * Captain Anna Maynard - Nina Sosanya
 * Lt Maurizio Savinio - Gerald Kyd
 * Lt Freya Jennings - Danusia Samal

Robot

 * Hargreaves is described as being tall and having a bowler hat.
 * The Doctor invokes the Three Laws of Robotics to stop Hargreaves from killing him on Dr. Akunin's orders.

Science

 * The Doctor mentions dimensional flux, gravitational anomaly, quantum phenomena, 3-D echoes, 4-D echoes and time eddies among other things as potential interests of disruption caused by the ergostorm.
 * The Doctor also mentions black holes and event horizons and time storms.
 * The Doctor refers to "Delahay's inverse cube law".

Organisations

 * Henrickson Biotech is a competing company with the company that the crew members of the HMS Aquitaine work for.

Places

 * The plant species aboard the ship is taken from the planet Ventrius III, a planet in the Alpha Kaylay system.

Continuity

 * Tegan refers to her aunt Vanessa. (TV: Logopolis)
 * Tegan once again describes herself as a "mouth on legs". (TV: Earthshock)
 * Nyssa obliquely refers to the death of her father Tremas. (TV: Logopolis)
 * Nyssa introduces herself as "Nyssa of Traken". (TV: The Keeper of Traken)
 * The Akunites infect, take-over and hunt their victims in a similar manner to the Krynoids. (TV: The Seeds of Doom)
 * Tegan goes to change her shoes, claiming she always wears the wrong shoes for the occasion. (AUDIO: Hexagora)
 * The Doctor will visit other places that orbit black holes like in his tenth incarnation or end up in situations in which the environment is massively effected by a black hole like in his twelfth. (TV: The Impossible Planet, The Satan Pit, World Enough and Time)
 * Just like how Nyssa writes messages to Tegan and the Doctor, who are at different points in time than her, on the walls of the ship, so will Sally Sparrow write messages to herself in the present at and from other points in time. (TV: Blink) River Song sometimes left messages for the Doctor scattered though time in a similar way. (TV: The Time of Angels, The Pandorica Opens)
 * The Doctor simplifies his explanation of time tracks using the analogy of a gramaphone needle and a record. He uses a similar method to explain transdimensional engineering to Leela involving black boxes and distance. (TV: The Robots of Death) He uses a soap bubble analogy to help Amy and Rory understand what sort of dimension they were trapped in but later claimed it was rubbish and wrong anyway. (TV: The Doctor's Wife)
 * The Doctor gives Tegan a yo-yo to measure the gravity. His fourth incarnation often used a yo-yo for the same purpose, as did his twelfth. (TV: The Ark in Space, Kill the Moon, et al.)
 * The Doctor later traveled with the decapitated head of a robot (Cyberman) that he affectionately called "Handles". (TV: The Time of the Doctor)
 * The Doctor considers himself "somewhat of an authority on time". This is because he is a Time Lord. (TV: The War Games et al.)