Irwin Allen's The Time Tunnel: The Nightmare Begins

In 1979, 20 years after it was set up, Project Tic-Toc was shut down by the American authorities. All hope of retrieving scientists Tony Newman and Doug Phillips, lost in the Time Tunnel in 1968, has been abandoned.  In 2025, four people reactivate the Time Tunnel in secret. They need to find Doug or Tony.