The Ambassador’s Secret

Head back up to the roof and down into Car 9, making your way toward Car 4. Along the way, Christina radios that she's heard noise from the VIP room upstairs — then contact cuts out. Something's wrong, and you need to hurry. (Car 5's electrified floor is still switched off from earlier, so you can just walk straight across it this time.)

In Car 4's VIP room, a note on the pool table warns you to come to Car 3 with the IC chip if you value Christina's life — and there's a Black Keycard sitting right next to it. Take both, then fight through the guards in the central control room on your way back down.

Use the Black Keycard on the door into Car 3. Past a couple of terrorists, a small safe room in the middle of the car holds assault rifle ammo, a memo, and a Small Key — take the key with you (the ammo can wait here) and save before taking the elevator up.

A string of FMVs plays out: Mason has Christina at gunpoint and demands the IC chip. The moment Jack hands it over, someone in a hazard suit attacks Mason, who dodges and escapes with both Christina and the chip — it turns out to be Pierre Simon, the Ambassador himself. Jack gives him Jane's pendant, and the Ambassador takes off running with a new urgency.

• Grab the first aid kit here, then in the next room take a Scope attachment (for the assault rifle you're about to get) and a memo.
• Head back down and across Car 4, then follow the Ambassador up to the second-floor VIP room.

In the back room, behind the painting and its two statues, another FMV plays: the pendant is one of two keys needed on the statue slots. Jack and the Ambassador use theirs together, and the painting slides aside to reveal a safe holding the real Secret Information Disc — the Ambassador is confident Mason will release Christina once he has it.

Take the disc and save at the bathroom panel. HQ radios in: it's time to track Mason down, and that means a trip all the way to Car 16.