Alan begins by uncovering the clues behind the greatest crime writer of all time on Burgh Island and at Greenway House and investigates what really happened in her much-publicised disappearance.

In London and Devon, Alan goes on the trail to get to know the real Miss Marple and finds out what inspired Agatha to create the famous silver-haired sleuth.

Alan investigates the inimitable detective Hercule Poirot, as he recreates that memorable walk and takes part in an immersive production of Witness for the Prosecution with fellow fan Robert Rinder.