 A series of bank robberies are taking place, with no evidence left behind. The robberies are the work of a group of thieves led by a chemist named Dr. Vespasian, who has created an invisibility formula called  Invisoscine . When Spidey investigates the robberies, Vespasian s dog, Brutus - who is also invisible - attacks Spidey. Brutus is thrown against a container of flour, which coats him & reveals him to Spidey. Spidey throws Brutus into a garbage can & traps him, but when police find signs of a struggle & pieces of Spidey s uniform, it is suspected that Spidey is dead. Vespasian sets another plan to rob a bank vault in motion, but Spidey has another plan; to trap Vespasian in the vault using ice cream toppings built into the security system. Sure enough, Vespasian enters the vault, and Spidey appears. Vespasian tries to escape, but Spidey buries Vespasian under mountains of ice cream toppings. The police are waiting outside & arrest the now-visible bank robber.