November ??

The two pairs get in their time machines, rev the engines, and peel off. Our original Tom and Jim, going backward and forward, visit universe after universe. They never travel more than a day in time in either direction. Sometimes they find no Tom or Jim, sometimes they find many.

They land in a universe where McCain won the presidency in 2008. To their surprise, Biden was his vice president! It turns out that in this world Biden is a Republican. Apart from that he seems no different.

Tom is fed up. The time machine is out of gas. Lately the universes they visit are full of Toms and Jims. There is no room in his house, and more Toms are arriving every hour. The neighbors are asking questions.

CHALLENGE: Write a satisfying, logically consistent end to this adventure!