The Good Liar ★★★

On their first night out together after meeting on a dating site for widowed septuagenarians (OK Boomer?), Roy Courtnay (Ian McKellen) and Betty McLeish (Helen Mirren) take in a screening of “Inglourious Basterds” at a London cinema. It’s the summer of 2009, and neither of these characters knows what happens at the end of Quentin Tarantino’s revisionist World War II extravaganza. Leaving the theater, Roy scoffs at what they’ve just watched: “Young people will think that’s what actually happened.” Betty isn’t so sure — she argues that the modern world has done more to clarify history than it has to obscure it.

More than just a crafty bit of foreshadowing (the full mirth of which isn’t clear until almost two hours later), this early scene appears to set up a pleasantly middle-brow thriller about our power to alter the past. If Bill Condon’s “The Good Liar” never manages to follow through on that promise — despite gesturing broadly in that general direction from time to time — this old-fashioned snack of a movie is still rather satisfying in its way. Pleasant and preposterous in almost precisely equal measure, the film never offers anything less than two all-time British actors having the time of their lives, which makes it hard to get frustrated that it seldom offers anything more. As far as Condon/McKellen collaborations (this is their fourth), it’s manna from heaven compared to “Beauty and the Beast.”