At a time when jaded cinemagoers are tantalised with all manner of tempting-sounding crossovers between film franchises, there is a certain pleasing simplicity to the central offering of The Good Liar, the latest film from Bill Condon. It is the first pairing of the legendary Ian McKellen and the equally celebrated Helen Mirren, thespian royalty who have somehow never before collaborated together, whether on screen or on stage. While it is tempting to bemoan what might have been – their Macbeth would have been brilliant, but then so would their Private Lives or Dance of Death – this adaptation of Nicholas Searle’s 2016 novel at last unites them. But does it justify such anticipation?

At first glance, the film resembles a slightly updated version of the kind of Hitchcockian entertainments that were in such demand in the Fifties and Sixties. Roy Courtnay (McKellen) is a successful but ageing con-man, tiring, along with his partner in crime Vince (Jim Carter) of small scores that bring in the tens of thousands, rather than the millions. What he wants is a spectacular “last job”, presumably that he can retire on, and as the film begins, he has found his “mark” in the form of Betty McLeish, a former Oxford don who is in poor health thanks to a series of strokes. Courtnay rubs his hands together in figurative glee, and sets about insinuating himself into Betty’s life, much to the horror and disdain of her protective grandson Steven (Russell Tovey). To Betty, Russell seems a decent and caring sort, if not without his eccentricities. But is she the full shilling as well?

To discuss plot specifics would be to spoil the storyline’s myriad twists, some of which are guessable and some of which are not. It is easy to see how the film might have been made a generation ago, with Trevor Howard and Celia Johnson in the roles so ably played by McKellen and Mirren, but it is also likely that the film would have been considerably lower on the swearing and violence that, at times, incongruously intrude upon the carefully written and acted game of wits that the lead actors are engaging in.

Make no mistake, The Good Liar is worth seeing for the two stars alone. As Courtnay, McKellen delivers the rumpled charisma and charm that he has specialised in throughout his latter-day career, cut through with something nastier and more feral when it has to be. (A scene on the London Underground, as he disposes of an intrusive mark, has a particular kick to it.) Mirren, meanwhile, has a trickier role to play, as this fine and intelligent actor has to convey an almost passive sense of gullibility for most of the first two acts, until her own motivations and intentions become clear.