Yes, there were even secret agents in the stone age! Fred Flintstone and Barney Rubble are recruited to track down the doers of evil - Green Goose and Tanya.

When master spy Rock Slag is disabled by henchmen of the sinister Green Goose, head of SMIRK, the Stone Age Secret Service calls upon Fred Flintstone, who is an exact double of Rock Slag, to impersonate the agent and track down Green Goose and his seductive accomplice, Tanya. Accompanied by his wife and daughter and by Mr. and Mrs. Rubble, Fred goes on a supposed vacation trip to Paris. Tanya has moved on to Rome, however, and the two families follow. Though Fred makes contact with Tanya, she leads him into a trap, and he and Barney Rubble end up as prisoners in an abandoned amusement park that serves as headquarters for Green Goose. Both men resist torture until the real Rock Slag arrives to put an end to Green Goose's ambitious plan to conquer all of Eu-rock. Once the madman is captured, he and his coconspirators, including Tanya, are sent off into outer space in one of Green Goose's own secret missiles. With Eu-rock saved, the Flintstones and the Rubbles return to their stone age homes.