Shadow Swans — Laura Thomas

Credenza R, a shockingly beautiful and well-read young woman, has lived inside the New York City subway system all her life; she has never been aboveground. Ruby Cooper, a filthy rich misanthrope, lives in an abandoned building adorned with hundreds of hummingbirds she has sculpted out of colored wire. Their lives collide, enabling them to find magic in the underground. When they discover a series of government-constructed tunnels connecting all the major cities on the Eastern seaboard, Credenza and Ruby embark upon the greatest, and most dangerous, adventure of their lives.