Fifth in the series of investigations by the Thursday Murder Club, a group of four delightfully quirky senior citizens who investigate murders for funsies. This case revolves around crypto-currency and deep storage of computer files–both concepts elude the seniors–but criminal activity is not the reason to read Osman’s books. Rather, the gratification comes in the gentle and quite humorous interactions of the four retirees as they squabble with one another, get into rows with their adult children, and wish they could chase down criminals, except their joints are too creaky.