Dating again quotes
As a child, Elizabeth viewed Songbird as a friend, but later came to hate it for keeping her imprisoned.
When she escapes, Songbird is intent on bringing her back, even if it means destroying anyone and anything near her, including Booker De Witt and even the Tower that she's kept in.
Green eyes indicate friendliness towards a person or object of focus, namely Elizabeth; orange indicates awareness but indifference to Songbird's surroundings; and red represents heavy hostility, chiefly towards Booker.
Once Booker and Elizabeth finally reach their airship, The First Lady, after the revolt at Fink Manufacturing, they begin to fly out of Columbia.
Suddenly, a statue on the ship calls Songbird by playing a specific tune built into it.
She and Booker use Songbird to defend against a Vox Populi attack on the airship, then to destroy the Siphon which had been limiting her powers.
Upon the destruction of the tower, the resulting electrical feedback disables the Whistler as an enraged Songbird flies back to reclaim Elizabeth.
However, the Songbird of the Columbia she opened the tear to emerges out on the other side of the window.