Amata wakes you up and lets you know that something bad happened - your father escaped from the vault, and the vault guards are also coming after you. Because of the recent change of events, you need to escape from the Vault - a shock to your conditioning about nobody ever entering or leaving the Vault.
Collect your stuff from your desk (including the baseball hat) and dresser (spare jumpsuits and your comic book if you haven't read it already), and head outside your room - you'll realize the severity of the situation when a Officer Kendall attacks you; they want you taken out. You can avoid killing him by sneaking into the men's bathroom as long as you flee before the radroaches attack Kendall.
On your way to the exit, the leader of the tunnel snakes needs help with rad roaches (because he is partially nyctophobic). Feel free to deal with that.
Gomez and Andy are found afterward; Gomez claims that he'll pretend he never saw you, and Andy is having fun torching radroaches. Andy is outside the medical office - you can enter to retrieve the bobblehead; however you cannot access the terminal (requires a key), nor can you pick the picture-safe (Lockpick 50, you need to be level 2.) Head into the atrium to proceed.
In the Atrium, you see Tom Holden and Mary Holden discussing reaching the exit. Tom makes a break for it, only to be shot down by Officer Richards and Officer O'Brian. Head up the stairs. The main entrance requires lockpick 100 - don't bother. Even if you manage to pick the lock, you can't proceed further.
After the room where Alan Mack bangs on the window, Security Chief Hannon will attack on sight.
Office Mack is currently in the interrogation room with Amata. If you told Amata to keep her gun, she will kill Mack; otherwise, you will need to dispatch him, whether to prevent him from harming Amata, or whether Mack learns of your location when Amata has the information forced from her.
To escape, you need both the key and terminal password. While you can gain experience for picking locks and hacking terminals, you can the key/passwords from the overseer (either by killing him, or threatening to harm Amata), or by obtaining the key from the overseer's dresser and password from the locker.
Once you have the password, you can open the passageway to the vault entrance and open the exit. Officer Park and Wolfe will come to attack in response. If you didn't kill Security Chief Hannon, he will be there as well.
Leave vault 101. While the officers will attack Amata, she can't be killed yet.
You have one last chance to adjust your character, in case you made a mistake within the S.P.E.C.I.A.L, G.O.A.T., or if you want to change your name, appearance or gender. However, there are NPCs available that can change your appearance as necessary.