When Peter accompanies Kate and her father, Dr Dyer, to Dr Dyer's lab, it's simply to show Peter their party trick - how static electricity can make your hair stand right on end. But it frightens Kate's dog Molly and she bolts. As they chase after her, the lab's anti-gravity machine catapults Peter and Kate back to the eighteenth century. The anti-gravity machine is stolen by the Tar Man, a notorious criminal, and without it Peter and Kate are stranded. They are befriended by a reformed cut-purse named Gideon, but Gideon has his own feud with the Tar Man and if his past catches up with him before Peter and Kate catch up with the anti-gravity machine, they'll never be able to return home. Meanwhile, in the twenty-first century, a massive police hunt for the missing children is being hampered by secretive NASA scientists...