Fred Pearson, star of the Central City Theatre's "The Great Gorilla" and friend of Barry Allen's, has been having blackouts, at the same time that a mysterious gorilla has been seen roaming Central City. As Flash wonders whether there is a connection, he also has to solve the mystery of the super-sonic vehicle that passes him like he's standing still.
Gorilla Grodd is the pilot of the super-sonic vehicle, and he has come to Central City to find Solovar, who is playing captive in the Central City Zoo. Grodd steals Solovar's "force of mind," and begins his plan to take over Gorilla City. But Solovar finds Barry Allen, explains the situation to him, and the two of them head to Gorilla City to confront Grodd.