False Negative (audio story)

 was the fourth and final story in the audio anthology, Encounters, produced by Big Finish Productions. It was written by John Dorney and featured Jemma Redgrave as Kate Stewart, Ingrid Oliver as Petronella Osgood, James Joyce as Josh Carter and Ramon Tikaram as Vikram Shindi.

Publisher's summary
When a strange travel capsule is activated in UNIT's laboratory, Osgood and Josh find themselves in a whole new world of trouble. Soon, nobody at UNIT HQ is quite who they seem, and the team discovers that the greatest danger they could ever face comes from within...

Plot
In a parallel universe, Osgood leaves Josh in bed and kills Sam, whom she has been holding captive since he betrayed her. Kate tells Shindi to deal with a potential intruder in Osgood's laboratory when an alarm sounds; he and Josh find a travel capsule with two seats and are unable to find Osgood. Josh locates another Osgood, mistaking her for his version, in a storeroom and kisses her.

Shindi finds Sam's body in a recycling bin and reports to Kate, who raises the alert level. When Parallel Osgood visits her, she sends her to inspect the transport capsule. Parallel Josh takes Osgood to do the same, but she is eager to return to the storeroom and declines to examine it. He assumes that she is acting oddly because of how they have killed Sam and kisses her some more, leading her to have a look at the capsule to get away from him and determine that it needs power cables from the storeroom. After meeting Shindi, she puts on a gas mask to hide her face and leaves Parallel Josh in the lab.

Josh looks around the base and meets Parallel Osgood, who kisses him and is celebratory about Sam's death being blamed on the intruders. She heads to look at the travel capsule whilst Osgood speaks with Josh, whom she had told to wait in the storeroom, and they plan to get their other selves away from the lab so that they can return to their universe using the capsule. Osgood distracts Shindi and Parallel Josh by claiming to have seen intruders whilst Josh heads to the lab with power cables for Parallel Osgood.

Checking her emails, Kate finds a message from Sam outing Parallel Osgood and Parallel Josh as enemies of the Leader planning on replacing him with his elder brother. She deduces that they killed him and that the capsule was planted to make UNIT believe that the murder was committed by intruders. Parallel Osgood realises that Josh is from a parallel universe and forces Osgood to remove her gas mask when she enters; she leaves with Josh in the capsule, telling her boyfriend that they are breaking up. Osgood and Parallel Josh are locked up, but escape before they can be executed. Osgood leaves through the dimensional breach and Parallel Josh is shot by Shindi before Osgood's machinery explodes.

In the other universe, Parallel Osgood forces Josh to keep her secret, threatening to kill his Kate and Shindi if he did not. Josh kisses her and calls her "Babe" in front of them, making them realise that Parallel Osgood is a fake. Josh finds Osgood and, believing her to be Parallel Osgood, pretends to be Parallel Josh and kisses her to take her gun before realising his mistake. They find the actual Parallel Osgood in the capsule trying to return to her home, but the energy levels spiral out of control and will damage reality. Osgood helps her boost the power and disappear, although she cannot tell whether or not she has survived.

Kate tells Osgood, Josh and Shindi that she has received word from Sam about something that he has found. Rather than have an awkward conversation, Osgood and Josh say that they will see one another later and part ways.

Cast

 * Kate Stewart / Parallel Kate - Jemma Redgrave
 * Osgood / Parallel Osgood - Ingrid Oliver
 * Captain Josh Carter / Parallel Josh - James Joyce
 * Colonel Shindi / Parallel Shindi - Ramon Tikaram

Continuity

 * The capsule was left behind by the Auctioneers in Vienna. (AUDIO: The Sontaran Project)
 * Kate is reminded of "an old family story" about the Inferno Earth, asking if her alternative universe counterpart has an eyepatch. (TV: Inferno)