Saunders actually nails her part as an amusingly stern commie bluestocking Yank, and Mackey has some useful fire, without quite being on Mia Farrow’s level in the evergreen 1978 version. If most of the other turns have a dress-up-box flimsiness, the same was equally true of that film, televised just about annually on Boxing Day, which boasted Peter Ustinov’s droll, grandstanding debut as Poirot. 

Branagh and his screenwriter, Michael Green, have added a few welcome twists to a plot many viewers will know inside out. Their tinkering feels reasonably in keeping with Christie’s methods – more so than the .45 Poirot whips out at the end to hold the whole cast ransom, for a disappointingly rushed unveiling of the guilty parties.

Branagh loves to have his camera sweep around the custom-built ship in grandiose long takes, taking in some wrap-around, fixed-in-post scenery that was never going to be a great substitute for actually visiting Egypt. One of the flashiest shots glides in and out of a contretemps without realising it’s committing the biggest error of all: making obvious exactly whodunit, when and how, at the very moment the murder occurs. 

If Branagh gets a chance to carry on with the series, he needs to throw his audience off-guard by trusting to a nimbler edit. After all these years, Christie’s smoke and mirrors can’t be expected to hold up if you’re mainly intent on using them to show off.

12A cert, 127 min. In cinemas from Friday February 11