It’s 42 years since bestselling crime writer Agatha Christie died, and yet her latest novel has just been released.

A couple of years back, in a rather cunning move, publisher HarperCollins did a deal with Agatha Christie Ltd to produce "continuation novels" featuring Belgian detective Hercule Poirot.

The company enlisted the services of contemporary murder maven Sophie Hannah, who conjured up The Monogram Murders in 2014 and Closed Casket two years later. Both books were huge successes.

Hannah did such a sterling job that the third book in the new series will be out in August. The Mystery of Three Quarters, as it’s titled, is set in 1930s London. The caper involves a series of letters, a load of outraged people, good old Poirot and a cryptic character named Barnabas Pandy.

Dame Agatha’s novels are obviously having a 21st-century revival of sorts, because her work is all over the big and small screens too. If you devoured the 66 detective novels she wrote in her lifetime, you will relish the spate of freshly made TV series and movies based on them.

Last year’s remake of Murder on the Orient Express, which starred everyone from Judi Dench to Johnny Depp, was great fun, though the creepy new Crooked House, with Gillian Anderson, Terence Stamp and Glenn Close in lead roles, was rather unsettling.

There’s more. The first image of John Malkovich as Poirot has just been released. The master thespian will play the much adored sleuth in the BBC’s adaptation of another Christie novel, The ABC Murders, on which filming began in June.