While surfing champion Skip Parker is sidelined by a telephone call, his friend, Barbara Gordon (who's celebrating her birthday!), awaits his return on the beach. Meanwhile, in a back room where Skip will take his phone call, a young lady beach hand is waxing up a surfboard. Joker plans to kidnap Skip. He has his henchmen put the girl in a sack down to her waist. She puts up a struggle as Jokers moll Undine sprays underneath the sack with Jokers sleep gas. Knocking her out. Undine takes a liking to the girls black ballet flats. She pulls them from the girls stocking feet and takes them for her own. They drag the sleeping girl in the sack by her pantyhosed feet from the room. Upon Skip picking up the receiver, He is quickly gassed by a hidden device and kidnapped by The Joker and his men Riptide and Wipeout and moll Undine. Barbara bears witness to Skip being carried into The Jokemobile and calls her father in hopes that he will, in turn, alert Batman. Meanwhile, Joker, hoping to become a surfing champion himself, has transferred all of Skip's knowledge and ability to his own brain with a terrifying Surfing Experience & Ability Trabsferometer & Vigor Reverser! Batman and Robin easily divine the location of Joker's secret headquarters at The Ten Toes Surfboard Shop, but they are captured there by the waiting Joker, Riptide and Wipeout, who paralyze them with handfuls of poisonous sea urchin spines! While The Joker and Undine depart for Gotham Point and the surfing championship, Riptide and Wipeout turn The Caped Crusader and The Boy Wonder into human surfboards!
Employing the use of a Portable Ultraviolet Batray, The Dynamic Duo burst free from their foam coffins and rescue Skip, who was locked up in a nearby bench, as Riptide and Wipeout make a break for it. Realising the only way to collar The Clown Prince Of Crime is to challenge (and defeat!) him in the surfing contest, Batman orders Robin to return to Wayne Manor, switch to Dick Grayson, and go to the beach and preside as a judge of the contest. Batman heads for Gotham Point Beach and discovers Joker employing the use of his newly acquired surfing prowess to frighten off all the other contestants. So The Caped Crusader grabs his surfboard, dons his swimming trunks, and heads out into the water to compete against The Joker and handily hang 10. The Joker is beaten, confronted by Skip Parker, and, knowing he has been found out, retreats with Undine, Riptide and Hideout to local surfing hangout The Hang 5, where The Caped Crusadress, Batgirl, joins The Dynamic Duo as they rout The Homicidal Harlquin and his henchies!
Meanwhile in Londinium, Lord Marmaduke Ffogg and his sister, Lady Penelope Peasoup, use a man-made fog to pull off a robbery...