Unspeakable horrors lurk deep beneath the surface of the ocean. Namely, middle-aged 1960s schlubs changing into too-tight scuba gear. You may think we’re weird for leading off with that, as it’s not really a selling point for a movie. Well, tell that to the makers of Destination Inner Space, who evidently thought it was compelling enough to devote roughly a quarter of the movie’s runtime to! The crew of the undersea Marine Science Institute is alarmed when they detect an unidentified vessel on their sonar, and also realize that their sealab is very obviously just an aquarium decoration. When they finally set foot on the alien ship, they do the only sensible thing and bring the most sinister object they can find back with them. Very soon, a horrible creature that looks like Blanka from Street Fighter grew scales starts wreaking havoc, and even the most adorable lil’ submarine may not be enough to stand in its way.