The Cognition Shift (audio story)

 was the fourth and final story in the audio anthology Hearts of Darkness, produced by Big Finish Productions. It was written by Lisa McMullin and featured Derek Jacobi as and Paul McGann as the Eighth Doctor.

Plot
Now in the Doctor’s body, the Master steals his TARDIS and uses it to escape.

Back in the present day, the Doctor tells the crew of his ship the story of what happened, and that despite appearances he is not the Master. They eventually believe him, realising that he has constantly been advocating for them to stop shooting people even though it would only hurt and not kill them. Now determined to finish the mission, the crew stick with the Doctor on his hunt for the Master, following footprints they find and getting attacked by the people of the planet that houses the Cognition Shift device.

Now masquerading as “Kirrios”, an identity he came up with when setting himself up as the leader of this planet, the Master pays Dorada for a device component and asks her to tell him about the “Master”. Since she believes that she’s helping the Doctor, she happily tells him all he wants to know. Learning that the Doctor is near and has been attacked, the Master starts preparing to leave, and is audibly upset that he may have been killed in the attack.

Since their attackers plan to take the group to the Master to ask what to do with them, they allow them to live and continue the journey, which takes them through guilt gas. The Doctor warns them that it will detect any guilt they have and show them what they think they deserve. The Scaramancer is forced to relive the time that she ran off with the Master and abandoned her sister, and though the group eventually manage to get her to safety, she believes so strongly that she deserves the pain that she tries to make them leave her behind.

Now ready to leave as soon as he needs to, the Master uses his new component to fix the Cognition Shift so that he can swap bodies with the Doctor again when he finds them. First, though, he convinces Dorada to trade bodies with him as a test that the machine works, and once he’s got her strapped into the machine he reveals his true identity.

Though she’s no longer being actively affected by the guilt gas, the Scaramancer keeps thinking on her past; recalls the time she had spent with the Master where he had forced her to keep rewatching the moment she left her sister behind, until she eventually became hardened to it. He’d lost interest in her when she stopped reacting to his cruelty, no longer finding her fun to torment.

On their way to find the Master, the Doctor comes across his own body. It tells him everything that happened, that she is Dorada, and that she now knows who the Master is. Though he’s suspicious, the Doctor is inclined to believe her and lets her stay with them. He finds out after a little while that it is not Dorada, and the Master has been faking. He swapped her mind with the mind of a bird instead, just to see the look on the Doctor’s face when he realised what he’d done. While he’s still reeling from the realisation, the Master hypnotises the Doctor’s crew so that they won’t attack him, but allows them to leave unharmed since he now has the Doctor.

At last, now that they are alone, the Master reveals his plan. He wants to put his mind into the body of every Dalek in the universe, creating an army of himself in a single move. This will put the mind of every Dalek into the body that the Master is currently inhabiting, which is the Doctor’s. Though the Doctor considers putting himself into the machine instead to stop the Master becoming an army, this would mean giving the Daleks his body, and therefore allowing them access to his TARDIS and Gallifrey. He can’t simply stop the Master putting anyone in, because it will direct the device to turn to the rest of the universe and give everyone else the mind of a Dalek.

Having broken free from the Master’s hypnotism, the Scaramancer returns. The Doctor and the Master both try to convince her that they are actually the Doctor, but she eventually decides to believe the one in the Doctor’s original body, because he talks her through the process of stopping the Master’s plan. Under his direction, she uses her own body to absorb the power of the machine until it’s been drained and can no longer function.

With the device dead and the escaping, the Doctor finds his TARDIS and takes the Scaramancer back home, where she asks to be called by her birth name, Lyric, again.

On the ship that the Doctor and his crew has used to reach the planet, the Master forces the hypnotised pilot to fly them to safety. Though they’re back in their own bodies now, the Master says that he committed many crimes when in the Doctor’s body, and that face is now a wanted criminal in many places all around the universe.

“He’ll have to do what he does best. Run, Doctor, run.”

Cast

 * The Doctor / The Master - Derek Jacobi
 * The Master / The Doctor - Paul McGann
 * Captain Morski - Colin McFarlane
 * The Scaramancer - Luyanda Unati Lewis-Nyawo
 * Dorada - Sandra Huggett
 * Peeler - Amanda Shodeko
 * Bandit - Alex Jordan

Worldbuilding

 * The Master plans to put his mind into the Dalek Pathweb.
 * The Master claims he will be more powerful than Rassilon and the Dalek Emperor.

Continuity

 * The Scaramancer relives the Master forcing her to abandon her sister at the Siege of Saracassar. (AUDIO: The Scaramancer)
 * The Doctor mentions that him and the Master chose their names. (TV: The Sound of Drums)
 * The Master in the Doctor's body says "I am the Master and you will obey me". (TV: Terror of the Autons, et all)