Deadheads

What's the secret of Patrick Aldermann's success? Well, he was bequeathed his aunt's gardened estate after her sudden death; his wife's wealthy father died leaving the couple a hefty inheritance; and several fatal mishaps among colleagues have allowed the milquetoast to rise in his company with alarming speed. His boss fears he's hired a serial killer, a suspicion that's compelled the CID's Andrew Dalziel and Peter Pascoe to investigate. Is it possible the mild-mannered accountant, whose only real side passion seems to be roses, has a thorny edge? If yes, then who's the next deadhead to be pruned from Aldermann's perfect life?