A Case for the Baron — John Creasey

Superintendent Bristow of New Scotland Yard needs help in tracking down several stolen precious stones. He is reluctant to ask but desperately needs the help of John Mannering aka The Baron, once mastermind jewel thief. Mannering suspects a crafty trap but accepts, once he lays down his own terms. But quickly things take a turn for the worst as Mannering finds himself involved in more than petty theft but a murder.