When Maj. Ben McBride (Patrick Wayne) returns to the lost island of Caprona to rescue his buddy Bowen Tyler (Doug McClure), he discovers his fellow explorer battling brutal cavemen and prehistoric creatures in this sci-fi adventure based on an Edgar Rice Burroughs novel. Ben and Bowen face these difficulties and more as they try to return to civilization. This sequel to The Land That Time Forgot co-stars Dana Gillespie.