Big Finish Doctor Who/Recap/S1/E08 Human Resources Part Two/NEDA

The Doctor distracts the Cybermen (the Mondas variety) by pretending to offer them his TARDIS. They'll need to get near it to make use of it, so the Doctor points them in the right direction.

The office warship has managed to defeat a lot of Cyberman ships. An improbable amount of them, actually. The HR manager points this out and offers his services to the Cybermen from now on. They sort of ignore him.

Lucie, Karen and La Résistance meet up with the Headhunter, who is still right miffed about Lucie being fired right after being hired. She's ready to quit her current job and strike out somewhere else.

The Time Lords who blocked the TARDIS throughout this whole season turn out to be the Gallifreyan "CIA": a group who feels that the Time Lord policy of "not interfering" doesn't involve nearly enough interfering. They plucked Lucie away from the office after her job interview (and dumped her with the Doctor). They couldn't risk her joining the war office... because they were already working on her. And since the office is propelled by a probability drive (something the HR manager didn't realise during his hostile takeover but which neatly explains the improbable amount of dead Cybermen), they didn't want her near the drive, and transmatted her into the Doctor's TARDIS instead. As it turns out, Lucie was destined to become an intergalactic war criminal in another timeline, and the CIA Time Lords meddled with her probability factors until she grew up to be just plain old Lucie. Her being near the drive would have ruined all that.

The Doctor convinces the Cybermen to steal the probability drive. It works wonders. For the Doctor, that is, because the thing was specifically programmed to destroy the designated enemies of the office, not just help whoever's holding it. The drive causes system failure in the Cybermen and they're rather easily defeated.

Lucie realises that she had her job interview on the same day as Karen. So it was Karen that the Time Lords were messing with, not her. The Headhunter is quite interested to hear that and offers Karen a job as her new assistant on her way out.

Lucie's free to go home. She and the Doctor banter for a bit, until she gleefully makes him admit that he'd like to keep her on board as his proper Companion from now on.