They reach Comstocks house, but the victory is short lived because Elizabeth is taken by the Songbird. Therefore, DeWitt must search for her inside the house and find out what happened.
Comstock house is divided in many areas.
Each of them has its own collectibles guide, because the game considers that the chapter named Comstock House takes place only in the first few areas and it features only one BioShock Infinite collectible.
After the cutscene, you have to cross the bridge and enter the building where you will find a statue of Elizabeth. Behind the statue is an entrance to another room, where a new enemy expects you, the Boy of Silence.
Theres a button behind him that summons an elevator, but if the Boy of Silence spots you he will send his minions after you.
When the fight is over and the elevator arrives, get inside and grab the BioShock Infinite Comstock House Voxophone which belongs to Elizabeth.
A LEASH; Elizabeth
Press the elevator button and as soon as the ride ends the next chapter, The Atrium, begins.