After experiencing a time-slip with an atomic clock, the Turtles find themselves in 1890, where they meet the famous detective Sherlock Holmes & his assistant, Dr. Watson, hot on the trail of Professor Moriarty, who has stolen the atomic clock with intentions to rule the future. The Turtles must retrieve the atomic clock before Moriarty uses it to change history & proclaim himself Emperor of the World. (thetvdb.com)