The special research vessel ALICE was the oddest ship that ever flew the ensign of the United States Navy; small, wooden-hulled and sail-powered, she would have been less out of place in the Navy of a hundred years ago - if it weren't for the electrician's nightmare of a christmas tree hanging from her main boom. The purpose of the "christmas tree" was to detect enemy submarines, it wasn't very good at that, but when lightning struck it proved itself highly efficient at...something else. For when the smoke cleared, there off the port bow was a long-ship. Full of Vikings. Throwing things. The ALICE had become...The Ship That Sailed The Time Stream,

"All hands—abandon present!" The Navy hadn't believed Leutenant Commander Joseph Rate and the crew of the yawl Alice when they had tried to explain their absence-without-leave as a freak display of time travel—and they hadn't believed Rate's warnings about how dangerous such travel could be. Instead, they had crippled the careers of good men for almost ten years, just long enough to decide that time travel worked, and just long enough to forget Rate's warning. So now Rate and the crew of the Alice are being sent back in time again, to nursemaid a landlubber scientist and a gun-crazy Company assassin on a mission to abort one of the pivotal encounters of all time and make the world safe for democracy at last. Or else unfit to live in . . .