"Cal, Winter, Ryan, and Boges lived through the 365 days it took to solve the Ormond Singularity, and then barely escaped from a lunatic bent on revenge. Now, a secret from Winter''s mysterious past has come back to haunt them ... With Cal away at flight school and a dangerous mystery to solve, will Winter be able to survive her own 30-day countdown? The clock is ticking, and any second could be her last."--From publisher.