Desmond walked into the Abstergo headquarters.
- Rebecca: They're probably holding your father on the upper levels. Same place they kept you. There's an elevator bank down the hall. Try not to let them see you.
- Desmond: They know I'm here, Rebecca. There's no way they don't.
- Shaun: This, this was a bad idea.
Desmond walked down the hall to the elevator bank, but was stopped by two guards.
- Guard: Hand over your weapons and come with me, sir.
- Desmond: I can show myself in, but thanks for the offer.
- Warren: I'd rather this not turn ugly, Mister Miles.
- Desmond: Then let me through.
- Warren: Subdue the subject, please.
After dealing with the guards, Desmond made his way to an elevator at the end of the hall.
- Rebecca: Fourth floor.
After reaching the second floor, the elevator stopped.
- Warren: Well, I see you've learned absolutely nothing since you left us. Walking into an elevator in the middle of a hostile environment. Really?
- Desmond: Where's my father?
- Warren: You'll see him soon enough. Now be a good boy and wait for security to fetch you.
- Rebecca: You're gonna have to climb the rest of the way.
Desmond climbed out of the elevator into the elevator shaft.
- Abstergo agent: He's headed up the elevator shaft!
Send someone in!
As Desmond climbed up to the fourth floor, more guards searched for him.
- Guard 1: Need eyes on him!
- Guard 2: He can't be far.
- Guard 3: Where the hell is he...?
After killing the guards, Desmond continued down a hallway.
- Rebecca: Your dad could be anywhere, Desmond. I'm sorry but I just don't know where he is.
- Desmond: That's okay. I do...
- Daniel: Give me the Apple.
Daniel shot at Desmond, who hid behind an Animus.
- Daniel: Let's not draw this out. You've got nowhere to go and I've got a gun. Speaking of which... It's the 21st century and you're still running around with only a tiny knife for protection? It's stupid. Alright Desmond. Game's over.
Before he could shoot Desmond, Daniel began to suffer from the Bleeding Effect.
- Daniel: Not now... Not...now... There is still work to be done. Niet! (No!) Get out!
- Desmond: What the hell was that?
Daniel fled the laboratory.
- Warren: What the hell is going on down there?!
Desmond pursued Daniel to a window overlooking the Animus training facility.
- Daniel: Get out! Get ouut! Get ouuuut!
Daniel leapt through a window onto one of a network of girders above the room, followed by Desmond.
- Warren: Enough is enough Mister Miles. I invited you here in the spirit of cooperation. But you've responded to my hospitality with only violence. I had hoped we might preserve you and further study your memories. But you're not worth the trouble. I hereby authorize the use of deadly force. Kill the bastard! And then bring me the Apple!
Desmond eventually caught up with Daniel and assassinated him, taking his gun and heading to another elevator.
- Desmond: Where's Vidic?
- Rebecca: Fifth floor.
The elevator arrived at the fifth floor and Desmond stepped out.
- Rebecca: Vidic's office is up ahead.
- Warren: You... You killed him... Daniel was like a son to me... A sickly son, perhaps... But one full of promise... He accomplished so much... and so well. And now you've taken him from me! From us! Like the Apple. Like Lucy. We want to help the world, Desmond. To save it from itself! But you keep getting in the way. All our hard work, ruined. You're a fanatic. All your kind. Maintaining the erroneous belief that WE are evil. That the work WE do is wrong. We ENRICH lives here. We SAVE and TRANSFORM them. But you... You just keep taking and taking what isn't yours!
Desmond fought his way to Vidic's office, until only his secretary was left standing.
- Secretary: Please don't kill me! I'll let you in!
Desmond walked through the doors and confronted Vidic.
- Desmond: Dad!
- Warren: Not so fast, Mister Miles. In case you hadn't noticed, I'm the one calling the shots. Now give me the Apple.
- Desmond: You want it? Fine. Here it is.
Desmond raised the Apple, manipulating the security guard nearest to Vidic. Using the Apple's power, Desmond forced the guard to raise his gun and point it at Vidic.
- Warren: Wait. No...
Under the influence of the Apple, the guard shot Vidic, before turning the gun on himself. Desmond then used the Apple to control every other guard in the room, manipulating them all into shooting themselves. Desmond then freed his father, who was tied to a chair.
- William: You never should have come here. You put everything on the line - for, what? So you could rescue your father?
- Desmond: Yeah.
Desmond killed both Daniel Cross and Warren Vidic, rescued his father and returned to the Grand Temple with the final power source.