He was one of a number of writers who submitted scripts to Andrew Cartmel in the waning days of the Sylvester McCoy era of Doctor Who. Had the show not been cancelled, Penswick's unproduced script, Hostage, might have been developed into a televised serial, according to an interview that Penswick gave to the fan magazine, Broadsword. Penswick later sent in the Hostage script to Peter Darvill-Evans, commissioning editor for the Virgin New Adventures line. This piqued Darvill-Evans' interest, and eventually led to a commissioning of the novel that became The Pit.