The Wonder Twins arrived on Earth when the craft they were travelling in crash-landed in the Kiscogee Desert, Arizona. Cold and hungry, their first brush with humanity came in the Delco Convenience gas station in Laconia. They were not welcomed with open arms, and the ensuing chaos attracted the attention of "Extreme Justice", who were stationed fifty miles away. Unable to communicate with the Justice Leaguers due to a significant language barrier, the Wonder Twins and "Extreme Justice" engaged in battle until the male alien, Zan (also known on Exor as Heart-From-Above), completely disappeared after Blue Beetle removed Zan's belt, which caused him to dematerialise. Unable to bear being separated from her brother, Jayna (called on Exor Water-Of-Life) removed her own belt, and disappeared also. The Justice Leaguers were left none the wiser as to who the Twins were or where they had come from.

In actuality, the removal of the belts had teleported Zan and Jayna back to their captor, the Slavelord Ovon Kelt on Dragonship, the third moon of the planet Velga. The Twins had escaped from Ovon and fled to Earth with his highly-prized Jrxan Flesh-Driver.

Returned to Earth with Ovon in search of the Flesh-Driver (which, unbeknownst to the Slavelord and the Exorians was now being used as armour by the Justice Leaguer Booster Gold), Zan claimed the right of Harin-Kataa, a sort of Exorian sacred duel also known as the "Folding Circle".
With the aid of the Justice League, Zan and Jayna are able to emerge victorious from the Folding Circle, thus winning legal ownership of the Flesh-Driver (still worn by Gold).

Zan and Jayna, pleased that - in Booster - the Flesh-Driver has finaly found a master who will not be consumed by the suit's draining of life-force, decide to stay on Earth to watch over the 'Driver, which is now their responsibility. The Extreme Justice Leaguers are happy to welcome the Twins to their team.