(Some Spoilers) One of many likewise movies released during the Cold War about the Commies, at home as well as in the USSR, trying to do their utmost to not only destroy our way of life. In this case destroy our, the Free Worlds, transportation centers and cause world wide panic and economic chaos by blowing up the vital Panama Canal. This will cause US shipping to travel almost 8,000 miles around South America, from San Fancisco to New York City, to get where it has to go without the use of the short-cut canal.
Having blown up the banana boat "Banos" and replaced it with a ringer, another boat that looks just like it, the Communist operative Captain "Scarface" Trednor, Barton MacLane, is planning to use it as a guided missile, with him doing the guiding, by plowing it into the locks of the Panama Canal. Setting off an atomic device that he has hidden on the ship Capt. Scarface plans to blow himself his crew and the canal to smithereens. The captain just has one little problem he needs someone who knows just what button, the red or the blue, to push to both activate and set the bomb off!
Having gotten German nuclear physicist Dr. Yager, Raldolph Anders, out of a Soviet Gulag the Commies want to dupe him into pushing the button by threatening to murder his daughter Isa, Virginia Grey, if he doesn't. Things would have gone all down hill for the good guys, the Free and Democratic World, if it wasn't for this scuzzy looking ship-hand Clegg, Paul Brineger. Scarface wanted to screw Clegg out of his pay in doing the Captains dirty work, sinking and killing everyone on the "Banos". It's that capitalistic disease, wanting to get paid for working, that in the end did the Scarface crew in by bringing the hero of the movie All-American, blond and blue eyed, Sam Wilton (Leif Erickson) on board. Sam had his own troubles and they didn't have to do with him having the burden on his head of saving the free world.
With Clegg confronting this Soviet Agent Kroll, John Mylong, in his hotel room whom Scarface told him to contact, in getting his pay, he ended up killing Kroll. Clegg is then shot and killed himself, by the hotel manager, where Sam is staying and looking to check out of the country, San Brejo. Sam finds a golden opportunity in getting his hands on the dead Krolls passport and using it to get on the banana boat "Banos" to take him back to the states; not realizing that it's set to go off in a nuclear explosion at the entrance of the Panama Canal Zone. The rest of the movie has Sam impersonating Kroll and then finding out that he's, Kroll, not only a commie. The ships Captain Scarface is using Kroll to talk the very reluctant Dr. Yarger, who the real Kroll supposedly helped escaped from a Soviet Gulag, to push the magic button.
With Isa on board we also have the handsome and clean cut looking Sam get to win her over, after she at first thought that he was that rotten Commie swine Kroll, and together with her and a number of other passenger Sam gets the drop on Scarface and his Commie. In the end has his entire mad and grandiose plan ends up at the bottom the Bermuda Triangle. Sam & Co. finally puts an end to this whole master plan on the part of Scarface and his Commie leaders in Moscow. Scarface and his commie cohorts who for all their smarts just couldn't find anyone, this in 1953 when the Soviet Union had both the Atomic and Hydrogen bomb, who knows where to push the right button in order to blow up the Panama Canal.