Sperantium
From Tardis Wiki, the free Doctor Who reference
Sperantium was the chemical that fuelled the imagination. It was harnessed by Ronan Sumners, who used it to power the teleportation system in New Port City.
Sperantium was prevalent in children, who had more avid imaginations, but decreased with age. Humans possessed more sperantium than New Port City's native Gornt population. (PROSE: Gatecrashers)
