The Truth About Rook (in Countdown)

But if Bond does reach the Facility.. I’ll be sure to thank him for the makeover he gave me.

If you ever ripped the voice clips from NightFire using PSound, one of the first things you'll hear are voice clips of Rook grunting and Dominique(?) screaming. Right after that is Rook's taunts and his speech for the last cutscene he appears in.

Now if you want to hear the rest of the mission's voice clips, you gotta go very deep into the voice clips.

Here's a picture of almost all the voice clips from Countdown (didn't include the Phoenix Soldiers/Commandos)

So we just jumped from voice clip #15 to voice clip #643 (or #645 if you don't want an unused file) for Countdown. While this isn't exactly the first time the file order does this, this is a gigantic leap. And why do you think that is?

Well it might have something to do with a cut mission called Hidden Agenda. 

But if Bond does reach the Training Facility.. I’ll be sure to thank him for the makeover he gave me.

If you weren't aware, there was a mission that was going to take place after Chain Reaction where you presumably would have discovered Drake's training program for his men to go into space (and possibly partake in it if M's line in Deep Descent is anything to go by) which only made it to the PC and GBA versions of the game.

So now we have two different locations for Rook to have his big moment. But I want you to pay attention to his word choice here.

Somehow, he’s worked his way into the complex.

I’m going below to cut the power so he can't follow.

But if Bond does reach the Facility..

If you think of this in the context of Alpha Sector, Bond has indeed worked his way into it, but apparently he hasn't yet reached the facility... It could be that he might be referring to Delta Sector but than it would just be an odd word choice. Also that thing about cutting the power is just an empty threat and you will never fail the mission if you take too long to make it to Rook.

Now if you think of it as in a power plant, it makes more sense. The complex refers to the part of the plant that's deeper inside than the warehouses and the facility could be referring to the training facility that the mission would have been known for. And if the PC version is anything to go by, he might have actually cut the power this time so Bond would have to go a roundabout way to get inside the underwater tunnel system.

Also there's the FMV name:

It means we weren't meant to get more than just Bond and him entering a vent to cap off Chain Reaction. Most of the other outro names at least indicate something significant (except for Night Shift) like Gondola, Mayhew Death, Lobby Rescue, Kiko Death, and Happy Ending.

And if you want one last thing to support my theory:

The subtitles for Rook's cutscene are right after the subtitles for Chain Reaction's outro FMV which would eventually have to be modified to account for Hidden Agenda's absence so the order makes sense.

Although I guess you can still consider this plausible with the weird order this game puts all the subtitles in.

Anyway, I think this explains a bunch about the weird specific voice clip order. It's entirely possible that everything you hear from Rook in Countdown was just repurposed from Hidden Agenda. This might even explain why he has a Phoenix Samurai when you fight him but I think we're going to speculation territory at that point.

Addendum (10/1/2020:)

I think this explains it well. These are Hidden Agenda clips. The most interesting point is that Rook's speech had an alternative voice clip that was the original. Maybe it was the one featured on PC? We may never know.