In 1968, Irwin Allen was in transition mode. At ABC, Voyage to the Bottom of the Sea was about to give way to Land of the Giants. Over at CBS, he had planned on a new series to replace Lost in Space, as that series was running on fumes after 3 seasons. Plans for a back-door pilot, however, had to be scrubbed because said pilot wasn't ready in time for presentation to network suits.
The Man From the 25th Century starred James Darren (ex-Time Tunnel) as an earthling, Robert Prentice, now known as Tomo, who'd been abducted by aliens as a youth, and trained to lead an invasion of his homeworld. The aliens were from a far advanced race. 500 years advanced, that is.
Unsurprisingly, Tomo finds that the aliens can't be trusted after all, and his loyalties are, in truth, to his native world.
The complete 16 1/2 minute pilot is available, but the lone poster on YouTube disabled the embedding code. For now, we'll serve up this morsel:
Had it gone to series, it would've certainly bombed, likely lasting less than half a season. Land of the Giants lasted 2 seasons at ABC, and it would be 5 years before Allen would land another series on ABC, this time an adaptation of Swiss Family Robinson (previously discussed).