Odyssey 5

In his continuing unsuccessful quest to make a huge amount of money from his knowledge of the future, Kurt marries a young woman who is destined to be a big star in the music world 5 years hence, but whose music is currently unpopular.
Then, one by one, the Odyssey 5 members start losing their future memories. In desperation, Taggart and Mendel consult a theoretical physicist who is lecturing at a local science fiction convention, pretending that they need help with the science in a time-travel novel they are working on. But all they are able to determine is that each victim has the urge to type a bunch of weird symbols on a computer screen just before losing their memories of the next 5 years.
Finally, Mendel is the lone survivor. As if struggling with his new marriage wasn't trouble enough, if his memory goes before he can figure out what is going on, there will be no one left to save the earth from ultimate destruction.