Inferno Protocol is a scenario for FIST involving a quick raid on a CYCLOPS base.
The PDF is 15 pages, with helpful diagrams, a solid cover, and big readable text.
Contents-wise, there's a lot of evocative description in here, but it's sometimes difficult to quickly pinpoint the mechanical bits amongst the rest of the text. In terms of the structure of the adventure, it's broadly a funnel of offices and regular CYCLOPS guards that terminates in one of three genuinely dynamic Metal Gear-y bosses.
The bosses are really the start of the show, and each has unique attack patterns and gimmicks and serves as a solid setpiece for a fight.
Overall, if you want a big classic video-game-y feeling boss fight with a little bit of runup, you should consider snagging Inferno Protocol.
Sidebar:
I promise I'm not trying to be mean here, but was this written with AI assistance? Some parts of the text feel like they have that machine lilt. The boss section definitely doesn't, though, so I'm not assuming anything, and I'm sorry if I got it wrong.