Published in Joe 90 Top Secret #12, 04/05/1969 - cover and 3 pages.
"Joe Joins The Circus" The arrival of a large circus from Crotia brings with it worries that it is out to do harm to England. Joe 90 absorbs the brain pattern of the world's top animal trainer to help while infiltrating the circus. He will learn of a plan to use the weapon from the human cannonball act to launch an explosive into the center of London.