Spoilers are precisely defined here. Rules vary by the story's medium. Info from television stories can't be added here until after the top or bottom of the hour, British time, closest to the end credits roll on BBC One. Therefore, fans in the Americas who are sensitive to spoilers should avoid Tardis on Sundays until they've seen the episode.



Assimilation² (indicia title Star Trek: The Next Generation/Doctor Who: Assimilation²) is an eight-part crossover comic book mini-series between the Doctor Who and Star Trek franchises, primarily featuring characters from Star Trek: The Next Generation but also the original Star Trek. It began publication on 30 May 2012 in North America. As of 2020, it is the only officially licensed crossover between the two franchises, though it remains non-canonical in the Star Trek franchise.

Publisher's summary[]

The two greatest science-fiction properties of all time cross over for the first time in history! When the Federation's most terrifying enemy strikes an unholy alliance with one of the Doctor's most hated antagonists, the result is devastation on a cosmic scale! Spanning the ends of space and time itself, Jean-Luc Picard and the crew of the USS Enterprise find themselves joining forces with the time-travelling Doctor and his companions, with the fate of the galaxy hanging in the balance!


Issue 1[]

Stardate 45635.2: The planet Delta IV is invaded suddenly and without warning by the Borg. The Prime Minister of Delta IV and her aide are beamed to a secure command center, where they observe the invasion alongside Starfleet personnel. The Prime Minister notes the atypical nature of this invasion — the Borg have never before attacked without calling for their target's surrender, nor have they attacked so brutally.

A Starfleet officer notes that the Borg are not working alone — they are joined by a cybernetic race the Federation have not encountered before.

At that moment, the Borg and their new allies beam into the command centre to attack and assimilate Deltans and Starfleet officers. The Prime Minister and three Starfleet officers escape to the USS Mattingly, a Starfleet Runabout, and leave the planet alongside other Starfleet ships.

In ancient Egypt on Earth, the Eleventh Doctor, Amy and Rory are engaged in a chariot chase with the Pharaoh's palace guards, who pursue them with vigor.

Passing a market stall, the Doctor grabs one of the support beams and pulls it out of the ground. Fruit and baskets fall in front of the palace guards, stopping them dead. The trio continue their journey to the Pharaoh's palace.

Once in the palace, the Doctor, Amy and Rory attempt to stealthily make their way to the Pharaoh's throne room. Rory accidentally knocks over and breaks a large blue vase, attracting more of the palace guards. As the guards move in, the Doctor climbs up to a curtain rail and uses the sonic screwdriver to detach it from the wall, pulling it down and over the guards.

The three move quickly to the entryway to the throne room, where Rory talks his way past the guards and into the throne room.

The Pharaoh asks how the three could have gotten into the throne room. The Pharaoh's Vizier claims they have "clearly gone mad from the desert heat" and says he will dispatch them. He demands to know the Doctor's name. The Doctor says the Vizier will know him better by his race — Time Lord. The Vizier is shocked, reacts disbelievingly, then attacks the Pharaoh. He then changes into his true form, revealing himself as a shape-shifting alien.

The Doctor retrieves a small green crystal, an "interdimensional prison cell", and uses it to "trap" the Vizier. He informs the Pharaoh that the Vizier was in fact an escaped alien criminal who was planning to "harness the kinetic energy from the Nile to fire up a tachyon pulse inverter" and destroy half of the Earth in the process.

Back in the TARDIS, the Doctor states he'd like to go somewhere "cool. And foggy." Rory hands the Doctor the green crystal and there is a flash of imagery — Cybermen and Borg. The TARDIS rumbles, Amy and Rory stumble, but the Doctor maintains control, saying that they're "almost there."

They step out of the TARDIS in San Francisco, about 1945. Rory and Amy are wearing period-appropriate clothing and the Doctor states this was his intended target all along. He describes San Francisco as a "bubbling cauldron of capers and investigations" and advises his companions that they're "bound to run into something unusual here."

At this point they step into a bar where they see an android in a pinstripe suit.

Issue 2[]

While completing a routine scan of Data's neural net, Geordi La Forge and Data discuss the philosophical implications of their technological upgrades.

Captain Picard sends Commander Riker on a mission to check on mining operations on Naia VII, an aquatic world. Riker takes Data and Worf with him. On the planet, they meet Captain Ochoa and Lt. Amato, two members of the Starfleet Corps of Engineers who are leading the mining operation, and Seelos, one of the indigenous, amphibious Dai-ai. Since the planet is largely covered in water, the mines are drilled from the tops of mountainous islands. Captain Ochoa, in charge of the mining operations, explains the difficulties of mining below sea level, and notes his concerns that "safety isn't the no. 1 priority". A pressure compartment suddenly fails and the section that Riker and his team are in floods. Worf rescues Ochoa and Amato, and Data rescues Riker.

In the aftermath of the flooding, Dr Crusher tells Capt. Picard that eight people died and twenty-two were injured. Geordi tells Picard that the mine has been operating with very low safety protocols, but were under heavy pressure from Starfleet to meet regular quotas. Picard tells him that the pressure is due to the need to rebuild the fleet after the loss to the Borg at Wolf 359.

After Riker returns to the ship, Picard tells him that upgrades to the ship's holodeck have been completed, and a new Dixon Hill adventure awaits him. Riker, Data and Crusher don 1940s attire and begin the programme. They hear the Doctor's TARDIS materialise, but put it down to a bug in the upgrade. The Doctor, Amy and Rory meet the Starfleet officers in a bar, where the Doctor immediately recognises Data as an android. Riker and Crusher assume that the Doctor, Amy and Rory are holodeck characters and the holodeck is malfunctioning again. Riker ends the programme and is surprised to see the TARDIS and its three occupants still present.

Worf escorts the trio to the ship's observation lounge. The Doctor recognises him as a Klingon, but notes that his memories are being altered. Before he saw Worf, the Doctor had never heard of them. In the observation lounge, Picard introduces himself to the Doctor, who notes that they "shouldn't be here, really." Deanna Troi scans the TARDIS travellers' minds, saying that Amy and Rory are slightly nervous but completely trusting of the Doctor, and sensing wisdom and sadness in the Doctor, but no ill intent. Picard is slightly sceptical.

The conversation is interrupted by news of the attack on Delta IV. When the attacking fleet is put on screen, Picard recognises the Borg and the Doctor recognises the Cybermen. The Doctor says, "We shouldn't be here, Captain." Picard replies, "I believe you're right..."

Issue 3[]

A Cybercontroller fitted with Borg technology hails the USS Enterprise and says, "You have no means of stopping us." Knowing that they will not be able to fight off the entire Borg/Cyberman fleet, Captain Picard orders the Enterprise to retreat and hide in the nearby Paertes Nebula. The Doctor tells Picard and his crew about the Cybermen, and Data scans the ship's historical database for any record of them. He finds a log entry from the Constitution-class Enterprise, commanded by James T. Kirk. As Data begins to relay the contents of the log, the Doctor is overcome with a flood of new memories...

The Fourth Doctor meets Captain James T. Kirk.

Stardate 3368.5: Captain Kirk, Spock, McCoy and Scotty investigate a Federation archaeological team on Aprilia III that has lost contact with Starfleet. Upon landing in a shuttlecraft, they are greeted by project manager Jefferson Whitmore, who assures them that all is well and gives them a tour of the facility. Kirk finds the staff suspiciously calm.

His team returns to the facility after dark. Trying to bypass an electronic lock, they are greeted by a strange man in a long scarf. He introduces himself as "the Doctor", opens the lock with his sonic screwdriver and offers jelly babies to the Starfleet officers. They find the researchers standing catatonically, with small cybernetic devices in their ears.

Spock and Scotty fight with the Cybermen.

Dr McCoy begins to remove the devices and revive the crew, but is interrupted by the arrival of a Cyber-Leader and two CyberNomads. A firefight ensues, but the Starfleet phasers are ineffective against the Cybermen. The Doctor uses the gold cover from Kirk's communicator to clog the Cybermen's respiration. After the Cybermen are defeated, the Doctor slips quietly away. The alien equipment that the archaeologists were investigating appears dormant, but it is not.

On Picard's Enterprise, the Eleventh Doctor remembers his meeting with Kirk, but also remembers not remembering it. The Cybermen appear to have abandoned their pursuit of the Enterprise. Captain Picard takes the Doctor, Amy and Rory to meet Guinan.

Issue 4[]

The Doctor and crew meet with Guinan.

In Ten Forward - the Enterprise's lounge and recreation facility - the Doctor is introduced to Guinan, the bartender, and they speak about the Borg-Cybermen alliance. Oddly, Guinan and the Doctor seem to be familiar with each other, which can be attributed to the fact that both are time- and space-sensitive (as the Doctor is a Time Lord and Guinan is El-Aurian.) Guinan also knows the Cybermen and the Doctor come from another universe, and it seems the Cybermen brought the two universes together and will cause Armageddon on a galactic scale.

Captain Picard receives a message from Commander Riker and the Doctor makes haste to the briefing room as well. The captain still does not trust the Doctor, but Guinan assures him the Doctor can be trusted - to which Picard says he reminds him of her since he does not know the true identity of either. However, it now seems that at first the alliance was heading to Earth but changed course. Data tells them the Borg-Cybermen went to the planet Cogen V. Picard decrees they go there at once and send down an away team. The Doctor asks that he, Amy and Rory join the Away Team as he is the only one with knowledge of the Cybermen, to which Picard agrees reluctantly.

The three of them join Riker, Worf and Data on a transporter pad and are all fascinated by it as the transporter energizes. The Away Team comes under fire soon after successfully beaming down to Cogen V, but the group neutralises the attackers with a combination of phasers and the sonic screwdriver. They find that their attackers were sentry drones that serve to defend the planet - and that there are Borg and Cybermen corpses around them. Commander Riker orders that a body of each species be taken back to the Enterprise to learned what happened on the planet, and The Doctor even brings one of the sentry drones to learn more.

In the sick bay, Dr Crusher performs an autopsy on both bodies and is shocked to learn that the Cybermen still have human brains. Off to the side, Counsellor Troi meets the Ponds and simply introduces herself by her first name - Deanna. She asks if the Doctor takes them on adventures, and they confirm it and tell her of their journeys with the Doctor. Troi also brings up another thing she sensed - that they are as protective of him as he is of them, to which Amy admits the Doctor is alone in the universe and he needs them more than they need the Doctor.

Meanwhile, the Doctor, Data, Dr Crusher and Geordi LaForge have been at work on the Borg and Cybermen bodies that were recovered. LaForge uses his VISOR in an effort to gain further insight and discovers something after examining both bodies: the Borg and Cybermen were killing each other. It seems an unbelievable prospect - but the Doctor is able to recover and display a video clip from the sentry drone that confirms this.

Lt. Worf calls for the captain to the bridge and tells him the Borg have contacted them. The Borg wish to speak to Locutus about the possibility of a truce. The captain cuts the transmission saying there will be no truce. The Doctor tries to convince him but Picard is adamant that there will be no truce.

Issue 5[]

The Doctor pleads with Captain Picard to open negotiations with the Borg, but the captain grimly refuses. The Doctor cannot understand his reasons, so then Guinan comes to Picard's ready room to tell the Doctor of his grim fate with the Borg some years ago. There, they learn that not only was Picard temporarily assimilated and named Locutus, but because of his knowledge of Starfleet tactics, thirty-nine starships and over eleven thousand Starfleet officers were lost at the battle of Wolf 359.

These memories and experiences that Captain Picard was forced to endure still haunt him. The Doctor finally understands now, but he still cannot break through to Picard, who wishes to return to Earth to aid in the rescue operations for the planets that already fell to the Borg and Cybermen. In the sick bay, Rory has to marvel at the advanced medical facilities that Doctor Crusher has. However the Doctor arrives there to tell the Ponds that Picard will not listen to reason. He fears that he and his companions will have to ally with the Borg or fight the Cybermen themselves. However Counsellor Troi tells the Doctor that maybe another person can make Picard listen to reason.

Amy goes to Picard's ready room to tell him that she along with the Doctor and Rory are going to confront the Cybermen themselves. Picard protests such an action, but Amy then tells Jean-Luc of the day she first met the Doctor. He met her when she was but a child and later in her life when she aged to her twenty's, and can see that he hadn't aged a day. She then brings Picard to the holodeck where the Doctor brings Picard into his TARDIS. Picard marvels at this almost unbelievable technology.

The Doctor takes Picard to the future and begins showing Picard the horrible events to come if they don't stop the Cybermen. At first Picard believes this all to be an illusion created by the Doctor, but he assures Picard it is not. Soon Qo'Nos, the capital of the Klingon Empire, is assimilated by the Cybermen. They soon go slightly further into the future and see that Vulcan, the Judoon, and even the world of Raxacoricofallapatorius and its people are assimilated. Then going even further into the future both see that Starfleet Academy was the last vestige of free people left in the universe. It soon fell though and the last remnants of humanity march in to be upgraded by the Cybermen.

With what Picard saw and some wise words from the Doctor, Jean-Luc finally concedes and will go against his judgment and ally with the Borg.

Issue 6[]

The Doctor, Amy, Rory, Picard, Riker, Worf and Data beam down to the desolate planetoid Tau Lee where they meet a party of Borg led by a drone who calls himself the Conduit and agree to be allies against the Cybermen. At first there is a bit of hostility as the Conduit was once a friend to Commander Riker. His ship was destroyed, which led to his assimilation by the Borg. The Doctor outlines a plan to catch up with the Cyberfleet heading towards the Borg homeworld and restore the Borg's executive library that was destroyed by the Cybermen which has rendered most of the collective inert. To get a copy of the library, he proposes travelling back in time. With Picard and the ship's counsellor, the Doctor goes to Naia VII to try to get supplies of gold, an effective weapon against the Cybermen, but the humans are unable to help as their agreement with the Dai-ai prevents them from mining for it. Picard begins talks with Seelos, leader of the Dai-ai, but it is the Doctor who swings the deal before travelling back in time with Amy and Rory to the Battle of Wolf 359. There, aboard a Borg cube, they encounter Captain Picard assimilated into the Borg collective as Locutus.

Issue 7[]

Locutus ignores the time travellers and they proceed through the Borg ship to a computer terminal where the Doctor copies the executive libraries. As the battle begins, the travellers slip back to the TARDIS and return to the Enterprise. Geordi the engineer has bad news, though, as, despite Borg enhancements suggested by Conduit, the Enterprise cannot achieve sufficient speed to catch the Cyberman fleet before it reaches the Borg homeworld. However, the Doctor suggests boarding the Cybership in the TARDIS. Once aboard, though, they are detected almost immediately despite splitting into two parties and soon find themselves up against the collected might of the Cybermen.

Issue 8[]

Worf's party, which includes Amy and Rory, attacks the engine room and manages to disable the engines. The Doctor's party, meanwhile, which includes the Conduit, Picard and Data, is captured by the Cybermen, but they are rescued by the arrival of the Enterprise firing a gold-infused particle beam. This destroys the Cybermen but not the Cyber Controller who is instead restrained by Data and the Conduit. This allows the Doctor to restore the Borg executive libraries. Immediately, the Borg set all Cyberships to self-destruct. They all race back to the TARDIS before the fleet explodes, but then Conduit announces an end to the alliance and attempts to assimilate the TARDIS. However, the TARDIS retreats from the attack, entering Data. Data fights back then Rory and Worf physically throw Conduit into the time vortex, ending the threat. With the Cybermen destroyed, the universes revert to the way they should be and the Doctor, Amy and Rory depart for their own universe. However the Doctor begins to suspect something is wrong before he leaves back to his universe. As the Borg have been brought back online, they believe in order to assimilate the Doctor they must master time travel.






  • Rory Williams' time spent as an Auton Roman soldier has left him experienced with steering chariots and, apparently, intimidating Egyptian soldiers.


  • The TARDIS experiences some "dimensional feedback" when it arrives in the Enterprise-D holodeck recreation of San Francisco in 1941.


  • Prisoners of some facilities used by the Atraxi, the Shadow Proclamation and the Visendi Detention Complex are transported in small green crystals, referred to by the Doctor as an "interdimensional prison cell and interstellar delivery service, all at once."
  • With the aid of Borg technology, the Cybermen would be able to conquer and convert non-human species such as the Borg, the Klingons, the Raxacoricofallapatorians, the Vulcans and the Judoon, as seen when the Doctor shows Picard a possible future.



  • A Klingon Cyberman is seen wielding a Bat'leth.



Story notes[]

  • A building appears in the holographic San Francisco with a sign reading "Tom's Bakery". A nearby street sign reads "4th". This is a reference to Tom Baker, who played the Fourth Doctor.
  • IDW considered producing a sequel[1] featuring a Doctor Who/Star Trek: Deep Space Nine crossover entitled Domination.[2] This was prior to IDW losing the Doctor Who licence.
  • The Doctor Who and Star Trek universes are depicted here as parallel realities. This is atypical for most Doctor Who stories, which treat Star Trek as solely a television programme. The elements of parallel universes and the Cybermen altering history may provide an explanation for this.
  • The concept of cyber-converted Raxacoricofallapatorians previously received a humorous contemplation in the form of the "Cyber-Slitheen" in Time Warped! (DWA 13)
  • Due to the crossing over of Doctor Who with the separately-licensed Star Trek franchise, and the fact that IDW still holds the comic license for the latter, this remains the only IDW Doctor Who publication not to be reprinted by Titan Publishing Group.

Production errors[]

  • In issue 2, an Andorian helms officer has a yellow uniform that suddenly changes to a red uniform.
  • In issue 3 of the crossover Scotty's rank changes from Cmdr. to Lt. Cmdr. many times.
  • In issue 4, the Doctor's bow tie changed to red. In the previous issues, he was wearing a blue bow tie.


External links[]