Kuldesh’s murder kickstarts an Elmore Leonard-esque caper plot in which various ­interested ­parties compete to get their hands on a consignment of heroin that had been in his care, resulting in a string of violent deaths alternating with comic set-pieces. As the gang springs into action they encounter art forgers, online fraudsters and drug dealers, as well as heartache close to home. It helps that their leader, Elizabeth Best, is ex-secret service, and is always having hilarious flashbacks to East Berlin in 1970. I'd love one of those books that's a caper around the world, but that also has some truth about the world, and also makes you laugh and has also has some of the aesthetic of Thursday Murder Club, but it's Da Vinci Code. It will take a lot more of the ­painful reality of old age to intrude on Coopers Chase before it stops being, for hundreds of thousands of readers, an essential refuge from the cares of real life.

If you are happy to let other pens dwell on guilt and misery, you can relax and enjoy this novel, which is superbly entertaining. Another show-stopper from Richard Osman and a must-read for fans of the Thursday Murder Club and The Man Who Died Twice. As the cold case turns white hot, Elizabeth wrestles with her conscience (and a gun), while Joyce, Ron and Ibrahim chase down clues with help from old friends and new. Naturally, however, Osman doesn’t miss an opportunity for comedy, and with Elizabeth ­occupied elsewhere, the mild-mannered Joyce – surely Osman’s finest creation – makes an effort to channel Elizabeth’s acerbity and imperturbability as she and her pals hunt Kuldesh’s killer. And former trades union official Ron continues to fight doggedly for justice — or at least as much as his bad knee will allow.You've got two working class characters, two middle class characters, two very strong women, two slightly more brittle men. But unlike most crime novelists, he ensures his book’s strength and momentum stem not from its plot or its thrills but rather its perfectly formed characters. Richard Osman’s first three Thursday Murder Club mysteries are among the 10 bestselling hardback novels since UK records began; I ­suspect only nuclear armageddon or an outbreak of antibiotic-resistant plague can prevent this fourth entry in the series from muscling onto the list.

The new book wastes no time allowing time to pass, which is sensible, yet we feel that things have moved on. Ron reaches out to longtime master criminal Jack Mason, who in old age has become a lonely soul after learning the hard way that “your henchmen are not real friends. If there is fault to be found, it is a recurring one throughout the series — namely that Osman’s two men have less to do than his two women, and as a result feel like extras around the main double-act. The foursome’s cosy relationship with the local Fairhaven police detectives – young Donna and her boss, Chris – is now established as a firm friendship; the wonderfully buff Polish handyman Bogdan is likewise reliably on hand.

The joy of writing this, is dark things happen in these books, but you can always talk about daytime TV and cakes.