A test rocket carrying wasps to outer space, to study the effects on them of weightlessness and radiations, crashes out of control back to Earth, into the jungles of Africa. The two astrobiologists in charge of the test mount an expedition to the Darkest Continent to retrieve their experiment, only to find the wasps have grown to giant size which are panicking all forms of life as they quest for food.

Annie (Ann Gillis), an orphan, (based on Harold Gray's comic strip but who is at no point in the film called 'Little Orphan Annie), is befriended by a fight manager, 'Pop' Corrigan (J. Farrell MacDonald). She brings him Johnny Adams (Robert Kent), a promising prizefighter. Annie gets the people of the neighborhood to finance his training. But on the night of Johnny's big fight, a gambling syndicate locks him in a gymnasium and it appears the neighborhood folks will lose their investment.