Killer instinct - Joseph Finder

Jason Steadman is a thirty-year-old sales executive living in Boston. He's a witty, charismatic guy who's well liked at the office, but he lacks the 'killer instinct' necessary to reach the top. To the chagrin of his ambitious wife, it looks as if his career has hit a ceiling: Jason's been sidelined.

But all that changes one evening when Jason meets Kurt Semko, a former Special Forces officer just back from Iraq. Looking for a decent pitcher for the company softball team, Jason gets Kurt, who was once drafted by the majors, a job in security. Soon, good things start to happen for Jason - and bad things start to happen to Jason's rivals. His career suddenly takes off. He's an overnight success. Only too late does Jason discover that his friend Kurt has been secretly paving his path to the top by the most 'efficient' - and ruthless - means available. After all, Kurt says, 'Business is war, right?'

But when Jason tries to put a stop to it, he finds that his new best friend has become the most dangerous enemy imaginable. And now it's far more than just his career that lies in the balance.