Undertow

Mysterious beings appear on the shores of dystopian Brooklyn in a saga blending action, suspense, and romance, by the author of the Sisters Grimm series.
Sixteen-year-old Lyric Walker's life is forever changed when she witnesses the arrival of 30,000 Alpha, a five-nation race of ocean-dwelling warriors, on her beach in Coney Island. The world's initial wonder and awe over the Alpha quickly turns ugly and paranoid and violent, and Lyric's small town transforms into a military zone with humans on one side and Alpha on the other.

When Lyric is recruited to help the crown prince, a boy named Fathom, assimilate, she begins to fall for him. But their love is a dangerous one, and there are forces on both sides working to keep them apart. Only, what if the Alpha are not actually the enemy? What if they are in fact humanity's best chance for survival?

Because the real enemy is coming. And it's more terrifying than anything the world has ever seen.

"Overflows with innovative, terrifying monsters—human, emotional and undersea.... Reads like an action movie."—E. Lockhart, author of We Were Liars

"Crashes over you in waves of emotion, allowing glimpses of family and loyalty, before dragging you into the depths of human prejudice, cultural mistrust, and political corruption."—A.G. Howard, New York Times-bestselling author of the Splintered series

"A solidly entertaining adventure with the perfect amount of romance and danger.... Buckley has created a phenomenal new heroine. Smart and snarky, with rough edges and a killer fashion sense, Lyric is a girl to be celebrated."— SLJ, starred review