The Good Liar seems, by the strength of its cast alone, to be one of the small film highlights of the year. A Dame and a Knight working together for the first time, in a caper film that would seem them surely sharing a witty spar or two. Alas, the dynamic duo proves to be the saving grace of a film that is lumpy, tonally inconsistent and ultimately forgettable.

The Good Liar is based on a book by Nicholas Searle and tells the story of Roy Courtney (Ian McKellen), a career criminal who has spent his life using false identities to ensnare people’s finances. In 2009, he secures a new target through an online dating website (the opening credits feature two senior citizens creating profiles over clacking typewriter font). That target is Betty McLeish (Helen Mirren), a widow with more than two million pounds savings and all too convenient series of strokes that may kill her within a year. Courtney thinks all his Christmases have come at once, but as the story develops, it becomes clear that he’s not the only one playing a dangerous game.

Released in early November with little fanfare, The Good Liar is obviously not being targeted by Warner Brothers as a big release, particularly with Le Mans ’66 also playing at the same time. The film’s core audience is the older audience members, those who enjoyed Downton Abbey or the two Marigold Hotel movies. There’s nothing wrong with this, of course, but the film’s tone is at odds with what its seemingly jovial caper story would suggest. Roy uses an injured knee to invite himself into Betty’s home and dodder around the place, pretending to be an innocent old man. These moments allow McKellen and Mirren to sparkle, but then the movie features sudden, shocking acts of violence, including a moment in which a character is thrown in the path of an oncoming subway train. It’s all well and good having violence in a movie, but it has to be earned and director Bill Condon doesn’t have the directorial stomach to pull it off.

To make matters worse, rather than gradually unpeel the layers of the story, the film chooses to use exposition-dropping flashbacks set during World War II. This grinds the film’s momentum to a shuddering halt, as well as robbing itself of its chief asset; the sparkling interplay between its two stars. Ian McKellen (who has worked with Condon three times before, in Gods and Monsters, Mr. Holmes and Beauty and the Beast) brings the same twinkling charm he had as Gandalf in The Lord of the Rings trilogy, while Helen Mirren continues to demonstrate why she is one of the most consummate actresses in the business. The two have never worked together on screen before, but their chemistry is crying out for another outing. Russell Tovey and Jim Carter are also on hand to provide support on either side, but neither of them really get big opportunities to shine.

The Good Liar could have been a sleeper hit, a film that defies expectations and grabs audience attention, but it looks set to limp out of cinemas with little in the way of good publicity and word of mouth. It has flashes of brilliance, but they are offset by a plodding, often dull narrative that can’t decide whether it wants to be a jolly jape or a twisting, turning thriller. McKellen and Mirren are left to do the heavy lifting, but not even their talent is enough to carry this dead weight.

Dir: Bill Condon

Scr: Jeffrey Hatcher

Cast: Helen Mirren, Ian McKellen, Russell Tovey, Jim Carter

Prd: Bill Condon, Greg Yolen

DOP: Tobias A. Schliessler

Country: UK, USA

Year: 2019

Runtime: 110 minutes

The Good Liar is in UK Cinemas Now.