Century 21 Merchandising acquired a line of plastic science fiction toys manufactured in Hong Kong, which they marketed under the name Project SWORD.

After Solo was merged into TV21, a second series of stories — text, illustrated by comics artists such as Ron Embleton and Don Lawrence — appeared.

An adaptation of the first episode of the TV series, "The Mysterons", set during its dénouement, and featuring audio flashbacks with some newly recorded dialogue.

The plot concerns Colonel White reporting to a military conference investigating the events of the first episode, surrounding Spectrum's first encounter with the Mysterons and its mission to protect the World President.

The story ends with the news that the Mysteron double of Captain Scarlet has returned to life and that the officer's loyalty to Spectrum can be restored with the aid of an advanced computer (a feature of Gerry and Sylvia Anderson's original TV script for the episode, but cut from the final version).