Author's note: This is from 2013 after I beat the game for the first time. Putting it up here for archive purposes.
Booker falls.
It takes only a few seconds for Elizabeth to notice, his movements sluggish, his right hand trembling so much that he can't shoot straight, the heavy breathing. But when he collapses onto the ground there's always a slight gasp that pulls from her, because she thinks it might be his last.
She can't allow that to happen.
She's light on her feet, barely hearing the gunshots that are flying by her head and body almost missing her and goes right to his side. Elizabeth does what she can; making sure Booker is alright, injecting him with medicine, talking to him.
'Keeps your eyes open!' she yells.
'Stay with me Booker!' she pleads.
When she sees his eyes flutter open, she knows she's doing her job, and when he wakes up, green eyes looking back to her blue she smiles a little, pulling him up to continue the fight.
Later when the battle is done, Booker and Elizabeth take their time surveying. They don't have much in supplies and Columbia is ripe for the picking, if you know where to look. Booker goes in one direction, finding food and ammunition, restocking, judging between the guns he has and the guns that are dropped during the battle while Elizabeth finds money, lock picks and just experiencing the outside. Granted she didn't expect that getting out of the tower would involve so much killing, blood and making sure this man she barely knows is alive but it's better than being in the tower with Songbird. So she might as well enjoy what freedom she has.