The Secret by Lee and Andrew Child

 This "Reacher" novel is set during Reacher's Army days. He's called to serve on a team investigating the murder of a group of scientists who had been working at a chemical company in India years earlier when an accident killed over a thousand people. Someone is systematically killing off the scientists while trying to find out who the boss behind the scenes was. The story keeps fluctating between Reacher and his team and the 2 women who are doing the killing. It's a good cat-and-mouse story with some exciting twists and turns toward the end.