The Unicorn and the Wasp (S04E07)

In "The Unicorn and the Wasp," the Doctor and Donna encounter the renowned author Agatha Christie at the estate of Lady Eddison. Their day takes a dark turn when Christie vanishes, and a corpse is discovered in the library. What unfolds is a thrilling mix of murder mystery and science fiction, complete with a jewel heist and a bizarre alien wasp. With time running out, the Doctor and Donna must unravel the enigma and uncover the truth behind the chilling events before it's too late.