- Published: 2010
- Hugo Award for Best Novel, 2011 —
- Nebula Award for Best Novel, 2011 —
- Locus Award for Best Science Fiction Novel, 2011 —
Stranded in the past during World War II, three researchers from the future investigate period behavior and seek each other out in a shared effort to return to their own time. By the multiple Nebula and Hugo Award-winning author of The Doomsday Book.