Given the enormous success of Richard Osman's debt novel and the current vogue for murder mysteries with comical overtones, it was inevitable that it would be adapted onto the big screen. So, the unfeasibly plush retirement home (basically an even more palatial Downton Abbey) under siege from an unscrupulous property developer (David Tennant doing one of his evil turns quite convincingly), is the setting, and its residents are pretty much every big-name actor over 70 from the British Isles, led by Mirren, Kingsley and Brosnan. The plot of course involves a murder, namely that of one of the co-owners of the retirement home, and the trio of pensioners get to sleuthing. This is pretty formulaic, so you're really just watching it for the stars and the cosy comic interplay between them.
For once, it's not that lkely that all four of Osman's sequels (to date) will be adapted for the creen, since they involve the same lead characters and it's doubtful whether the actors even want to commit to such an extended series on the same theme at this advanced stage in their careers.
6/10