It Can't Be Done!
Storyline: A scientist takes a handgun back to 1756 for protection when confronting a gunsmith he hopes to stop from developing his 'ultimate weapon' so that wars will not be as devastating. His fighting skills are quite poor, however, and the gunsmith and his apprentice easily overpower him. He panics, drops the gun, and hits the recall button for his time machine. He doesn't realize he has supplied history with the gunsmith's 'ultimate weapon'.
Credits: