The Good Liar covers its tracks a little too well.

Although there have been a few remakes of “Bedtime Story”, such as “Dirty Rotten Scoundrels”, Bill Condon’s twisty con man mystery is the first to remove the comedy (unless, I guess, you count “The Hustle”) and play the story straight. Despite Condon’s best efforts, though – and an acting masterclass from McKellen and Mirren – “The Good Liar” forgets to drop enough clues and hints so that its big reveal feels rewarding and thematically satisfying. As it is, it remains an entertaining potboiler worth watching for the sterling work of the cast and a few nice visual flourishes.

It all begins innocuously enough with the recently widowed Betty McLeish (Helen Mirren) meeting Roy Courtnay (Ian McKellen) through a senior citizen dating site. But Roy is a veteran con man looking for his next big score only this is one job which is going to leave a mark.

There’s a wonderfully sly moment early in the film as Roy enacts his plan to insinuate himself into Betty’s life where we’re transported to her suburban home though a wonderful aerial shot. Condon frames the neatly planned and perfectly manicured suburb from the air like the streets are an occult symbol carved into the bucolic countryside. It’s a subtle harbinger of the wickedness that this way comes as the arch con-man meets deceptively easy mark.

Unfortunately, it’s a moment of sublime subtlety that isn’t repeated as the remainder of the film seems content to rely on the performance of its leads rather than the intricate construction of its story. McKellen is tremendously watchable as he takes Roy from doddery old gent to ruthless criminal and back again in the blink of an eye and Mirren matches him step for step as the widow hiding secrets of her own.

What twists and turns there are feel inevitable from a certain point in the movie and while it all makes sense in the end, it never feels like it’s all slotting into place like some sophisticated masterplan, more like it’s checking off a step by step checklist. It’s worth watching for the delicious double act of McKellen and Mirren, but don’t be conned into thinking you’ll be getting a deep and complex mystery – that’s the biggest lie of all.