After four seasons of spies, saboteurs, monsters, aliense, mad scientists, and crazed Admirals, Voyage to the Bottom of the Sea closes its run with a fairly quiet time travel yarn which is short on logic, but long on good performances and fun. After The Time Tunnel was calceled the previous season, time travel became a previously untapped subject in Voyage's fourth year. Henry Jones returns as Mr. Pem ("A Time To Die"), givng us an adversary who is dangerous, yet still oddly likable. He has a genuine plan in mind this time around, which begins with the destruction of Seaview. While the lack of budget is apparent and robs the episode of needed scope, the subject is a refreshing change of pace for a series which had long worn out the welcome of monster and aliens. Even though Voyage was the one Irwin Allen series whose format did not require a wrap up, "No Way Back" feels very much like a finale. The episode begins with the deaths of everyone except Nelson and Patterson (ironically the first two regular actors to pass away after the conclusion of the series), and a quiet resolution. While nothing is actually ended aside from the episode itself, just the feel of the final moments, including the soft, light music, made for a bittersweet farewell to a fun series. Richard Basehart is a delight. In the last two seasons, he rarely seemed interested in the outrageous goings on, however he was apparently pleased with the script - or the fact that there were no more comiung. Both he and David Hedison carry the episode nicely, however everyone has something to do one last time. The story is slight, the time travel inane, yet there is a charm to the story which outweighs most criticism. The mere fact that there isn't a monster or alien to be found adds immeasurably to the hour. Everything goes by in brisk fashion, glossing over plot holes, and having characters reach conclusions without any real work (i.e., Nelson says he was "studying" the explosion, yet he never had a free moment to do this). The music is well spotted, and Henry Jones ad libs some amazing lines as he and Nelson leave to go back in time to Seaview.
Perhaps I overpraise this one, but it is the best finale of any of the Irwin Allen series, and a very dignified climax to a series which deserved better than it had received in its last two years. It is, frankly, an episode which makes one wish there had been a fifth season. Well done, and worth a watch.