A Way Forward
From Tardis Wiki, the free Doctor Who reference
A Way Forward was a model created by Sherman Pegg in 1986 to represent his theory of time travel.
He entered it into a science fair staged at the Summer Park Mall. The Second Doctor admired his creation and made small corrections to the boy's formula, unaware that Sherman understood the theory.
Sherman went back in time and stopped himself going to the fair and his model disappeared. Reality changed rapidly as Sherman altered history, only making it worse as he tried to reverse it. The Doctor corrected the changes and help Sherman back into his normal time, putting the suggestion to him that they work on a different science fair entry together. (AUDIO: The Way Forwards)
