The Kronos interference

When physicist Jacob Newman is pulled from his family, his job, and his whole life to investigate a strange vessel discovered at the bottom of the South Pacific, he finds evidence of time travel, along with implications that a judgment day against mankind is imminent. But it isn't until he cracks the time travel technology and uncovers a startling link to his own family history that he undertakes a dangerous mission back to 1924 to kill Adolf Hitler and undo a horrific episode of Earth's violent past. The results are catastrophic, and soon he discovers much darker forces working against him--forces he must overcome if he hopes to save humanity and see his family again.