In 1926, Agatha Christie went missing for 10 days. But why? Did she have amnesia? Had she suffered a nervous breakdown? Or was it something to do with a Giant Alien Wasp..? Arriving in 1930’s England, the Doctor and Donna visit Lady Eddison’s manor where they are delighted to bump into the legendary crime novelist.

Of course, where Agatha Christie is involved, a mystery is never too far away and the Doctor and Donna soon encounter a dead body in the library, a jewel thief, poisoned cocktails… and the Vespiform, a giant alien wasp-like creature who’s seeking revenge.

Guest stars Felicity Kendal as Lady Clemency Eddison and Fenella Woolgar as Agatha Christie.