"Alright my little friend, before you die from that foam, I want you to tell me something that's very important—do you understand?"
The little people discover an old communications station (in a storm drain) capable of reaching Earth. Meanwhile; a giant scientist has invented a "truth foam" that when sprayed upon a suspect produces instant confessions. Steve becomes covered in the foam minutes before the giant scientist discovers his foam to be lethal!
While hiding in a drain pipe, Steve and Fitzhugh find a room full of electronic equipment on a human scale, which they learn is from a lost American space flight. When Steve tries to radio Earth, the signal is intercepted by the giants, who attempt to trace the transmitter station. Steve is captured and the giants use a mind-controlling foam on him, whereupon he reveals the location of the transmitter. Mark rescues Steve, and once he recovers from the drug they are able to destroy the equipment room before the giants can dig it up.