[1] Posing as a trio of young rock 'n roll musicians, The Impossibles were actually crime fighters, with superpowers, dedicated to battling evil supervillains of all shapes and sizes.

[2] When performing for their adoring fans (usually star-struck, screaming teenyboppers), the lads would play their mod, futuristic-looking guitars atop an equally futuristic bandstand (emblazoned with their "Impossibles" logo on the side, a la Ringo Starr's drumkit) that could convert into a car (the "Impossi-Mobile"), or a jet (the "Impossi-Jet"), a speedboat, or even a submarine.

As with many Hanna-Barbera characters, the Impossibles were topical and inspired by the times, in this case resembling the rock 'n roll groups of the mid-Sixties.

After a series of funny superpowered forays, the Impossibles capture the villain and return to finish their concert.

A new text-based story, specially written for the annual was "The Impossibles Cure a Doctor", with the villainous Herr Doktor Adolf von Tischklautz.

They are also joined by a fourth member, a girl called Esme Santos who has control over magnetic fields, who nicknamed herself Cobalt Blue.