Here's a map of the level.
Map - Rapture Central Control
1. The Vita Chamber - Audio Diary
2. Baby Status - Audio Diary
3. Mind Control Test - Audio Diary
To the left is SuChong's The Vita Chamber audio diary. A Lockbox and Coffee are here as well.
The room is rocking back-and-forth. Find supplies from this Pneumo on the right.
To the right is a Circus of Values, Napalm and a corpse. The door to Ryan's office ahead is jammed.
Farther left is this table with a Lockbox, Antipersonnel Auto Rounds, and a First Aid Kit. A corpse and a storage crate are on the floor.
Access to a U-Invent and a Gene-Bank is also here.
Climb the left stairs all the way up to find this vent. Crawl through.
Emerge from the vent then drop into this pivotal room. SuChong's Baby Status audio diary is on the counter ahead. His Mind Control Test audio diary is to the left. An EVE Hypo is farthest left, and a Frag Grenade is on the floor. Behind you is another Frag Grenade, a First Aid Kit, Pistol Rounds and Armor-Piercing Pistol Rounds.
Proceed through this door.
Follow the hallway to this window, where you can see Ryan casually practicing his putting game. He has a lot of explaining to do.
His explanations seem to fit. You are the creation of Frank Fontaine.
Ryan opens the door to his assassin. It all seems too easy. Approach Ryan to trigger the cutscene.
Much speculation surrounds the seeming illogic of Ryan's capitulation, much of it focusing on the previously-seen Vita-Chamber.
You automatically retrieve Ryan's Genetic Key. Enter his office and find cash in his desk. Place the Genetic Key in the slot seen ahead - the Self Destruct Override.
Wait for the machine to do its thing, and for Fontaine to tell his tale.
Little Sisters come to your salvation. Whether you've been rescuing or harvesting them, the result is the same. Follow the Little Sisters to the safety of Olympus Heights.