"They are beautifully dressed, usually in dark mohair business suits. Fine, light weight raincoats are a trademark. Their passports always show them as professionals, and they look it. They stay at grade A hotels, always together. They always shop in Oxford Street and visit Westminster Abbey and Buckingham Palace. But they're more interested in sporting events. They keep to the same circuit every year the Grand Prix of Monaco, Epsom for the Derby, Le Mans, Ascot. ..."
They sound like a team of Temple Fielding's travel scouts, but Detective Inspector John Candlish of Scotland Yard is actually describing...