Bioshock Infinite Walkthrough Part 47: Family Reunion (Grand Central: Main Lobby to Turn Stile)
Ar the top of the big lobby, have Elizabeth open the door with her hairpin. Immediately after that have her open the tear directly in front of Booker. This will give him vitally needed cover. There are 2 Vox Snipers just in front of you. The cover will stop them from immediately killing you. Booker should use the cover to easily, and quickly, kill the pair of them.
With them dead the rest of the area will open up. The turn stiles ahead are one way so head over to the left first toward the Bookstore. Go over to the Door (1 Pick) and have Elizabeth open it. Go inside and start searching around. Begin with the counter just beyond the door. Hit up the Cash Register for some Silver Eagles. After that go over to the right and to the end of the counter. There you will find a Gear Box. Grab it then go over to the right and look along the bookshelves on this side of the store. You will find a Voxophone: Rosalind Lutece “A Window”.
With that one in hand head down the stairs to the lower floor of the Book Store. Go over to the right and quickly grab the Voxophone sitting on the table: Ronald Frank “Sally”. Take cover as the Vox will likely attack around now. Kill the 4 of them off then resume your search. There is a Lockpick along the right-hand side of this area nearby the chair, just past where you got the Voxophone “Sally”. This will open up a new area in the Salty Oyster that you passed a little way back. It is worth it to back track as one of the rewards is an Infusion.
Head back through the station toward the Salty Oyster. You will need to fight your way through a few small groups of Vox on the way so be wary as you get there. Once you make it into the bar, jump the bar and head over to the register. Look beneath it on that side to find the button you need to hit.
With the button pressed it will unlock a previously sealed door nearby. Head inside and look on the counter. You will find the Return to Sender Vigor, the Infusion, to the right of that 2 Lockpicks and over to the left, in the corner, in the basin a Voxophone: Rosalind Lutece “One And The Same”. Grab the Voxophone and the Vigor first and foremost. After that make your way back to the book store.
If you want to grab another Lockpick then you will want pause in the room with the massive Comstock statue. Look to the right of the statue to find a Freight Hook. Grab onto that using the Sky-Hook. Once oyu have jump onto the base of the statue, right by the back of its feet. Look around in this area to find the Lockpicks. From there just bee line it back to the book store and head on through the turn stile onto the next part of the area. After that just head to the Turn Stile and head on through it.
Once through the turn stile head over to the right. You will find an Elevator that has a combination lock. Head back over to the left and look at the first desk in front of the turn stile. There you will find the combination you are looking for. There is a quick scene with the Songbird searching for Elizabeth. After that head back over to the right, to the elevator, and talk with Elizabeth. She makes Booker promise something. After that head into the elevator to get to Downtown Emporia.