Anastasia and Edward Upston are summoned to the Order of Time's London headquarters to provide testimony. Their friend and mentor Dr. Alfred Gregorian has been charged with violating the time-traveling society's rules in relation to their trip to ancient Egypt. The twelve-year-old twins are determined to defend Dr. G and to get a closer look at the inner workings of the Order and its secret academy.

An unexpected turn of events leaves the twins stranded a thousand years in the past during the Viking Age. Hopes of returning home become secondary when they find themselves caught in the midst of a power struggle between Odin and Loki that could instigate the end of the Nine Realms. Surviving the Viking Age long enough for Dr. G and the Order to rescue them may be the hardest thing they ever do. If they can ....