Icarus by Russell Andrews
When a burglary goes wrong on the opening night of his new restaurant, Jack Keller is left a widower and suffering from several bullet wounds. In emotional and physical turmoil he becomes a self-pitying recluse, until Kid Demeter, a young man Jack once regarded as a son and who is now a formidable physiotherapist, bullies him into better health. Then Kid is found dead, but Jack cannot accept the view that his death was either accidental or suicide. Knowing he owes Kid for getting his own life back on track, Jack starts to investigate Kid's personal life and discovers he was a serial womaniser. He begins to identify and locate these women, but every time he speaks to one of them they end up dead. Then, as he edges closer to the truth of Kid's death, he realises that his wife's murder was the catalyst of all that followed.