"Professor... what's going on?!"

Good question, Ace.

The last ever classic Who story to be recorded, Ghost Light, is something of a period-piece puzzle - with a few pieces missing.

But it does include dinner-suited monsters, gun-toting maids, an insane explorer, a simian sermoniser and a Neanderthal butler (doesn't every home have one?). This madhouse is presided over by a dusty but upwardly mobile photophobe, with high treason on his ever-evolving mind.

But he doesn't bargain on the devious Doctor and the arsonous Ace, ably abetted by a racist rozzer and an uncontrolled control experiment.

Enter the angelic, anally retentive Light and the Earth is in imminent danger of being purged in a fit of OCD pique.

But can Jim and Martin shed any light on proceedings? Listen in and decide for yourself.