So why doesn't Mason Bridges (Horton) play poker any more, not even a friendly game in the railway club car. The suspense doesn't really kick in until the last 5 minutes, but then it's sweaty-palms time in spades. A lot depends on that excellent actor Robert Middleton making Sam Klinker (apt name) rather dislikable. That way we can believe a prudent businessman like Bridges would risk ruin just to wipe the smile off Klinker's smug face. The revealing tale is told appropriately in flashback, and reviewer Hitchcoc is right—it's a strong entry, though there is a key development that remains something of a stretch. The hunky Robert Horton was in a number of these early episodes before joining the cast of the super-popular Wagon Train series. After abruptly quitting that series, he tried to make the jump into movies, but apparently it didn't work out. Too bad, he was an excellent actor as this 30 minutes shows. Anyway, I enjoyed Crack of Doom as a boy and am glad to return the favor, even 50 years later.