Jeremy had messed up his atomic messenger device, and sent three messages throughout history.
One was sent back to the time of the Dinosaurs, somewhere in the asteroid belt. The message was “I like pie!”, and it caused a asteroid to plunge into the Earth.
One was sent to the late 1930s, somewhere in Germany. The message was “BOO!”, and it caused an Austrian to start WWII.
The last one was sent to the present, causing Jeremy to mess up his atomic messenger device.