Federal Agent Rex Bennett (Rod Cameron) goes up against a group of saboteurs. Republic liked the Rex Bennett character enough to have him in a following serial, Secret Service in Darkest Africa. Here are some interesting notes from Valley of the Cliffhangers, by Jack Mathis. In this one the fist fights are plentiful, a staple of serial action, and the Lydecker brothers set up a really elaborate and creative death device in Episode 8 that Vivian needs to be rescued from, building up a really good cliffhanger.
Episode 2…"Originally entitled "Oriental Torture," which did not pass Hayes office muster, this episode was re-named Japanese Inquisition."
"Tight shooting schedules and the numerous scenes filmed each day for a serial occasionally resulted in minor production lapses, such as Rex's office door, which was lettered to read "Private" from inside and thus [was] incorrectly backwards from the hallway entry point."
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