ELEMENTARY, MY DEAR TURTLE

'Elementary, My Dear Turtle' is episode number 156 of the 1987 Teenage Mutant Ninja Turtles cartoon series. The episode is a part of the ''Vacation in Europe'' series from 1992-1993. The ''Vacation in Europe'' series take place during season 4. This episode of the show was written by Dennis O'Flaherty.
This is the final episode where Raphael is voiced by Hal Rayle.
On their trip to Europe, the turtles and April O'Neil visit the United Kingdom. A time machine inside a museum accidentally transport them back in time from 1990 London to 1890 London. Donatello notice a lot of changes, like the clothes of the guard, and it's not the same guard. The TMNT and April help no one other than another fictional character, Sherlock Holmes, to fight Professor Moriarty. Professor Moriarty tries to change the future into one where he rules. The time travel is only temporary, and they soon go back to 1990.