When the Shah of a foreign nation wants Vicki as his wife, she gets out of it (or so she thinks) by announcing that she is secretly engaged to Batman!; Batman and Robin are escorting a prisoner transport when their plane crashes on what appears to be a deserted island. But the island is controlled by the murderous pirate Lars Veking, and Batman and Robin find unexpected brothers-in-arms in the form of the prisoners they are escorting. One by one, the prisoners use their criminal talents to help defeat Veking. Afterwards, the prisoners turn on Batman and Robin, who are forced to flee. The prisoners steal Veking's submarine and head for the mainland, only to find the Police waiting for them. Batman and Robin were stowaways in the torpedo tubes!