After six and a half years as Prime Minister Tony Blair's principal private secretary and chief economic adviser, Jeremy Heywood knows how to cut a deal. He also possesses a world-class Rolodex. Heywood has dealt with just about every executive doing business with the British government and, as Blair's sherpa, has negotiated with senior foreign officials to prepare Group of Eight summits.

Morgan Stanley apparently thought that Heywood's experience was an appropriate apprenticeship to investment banking: The firm has hired him as a senior M&A banker in its London office starting this spring. Heywood left Blair's staff at the end of last year.

After enduring the pressure cooker of 10 Downing Street, the 42-year-old was ready for a change. "I'm essentially at the top of my career path," he says. "It doesn't get any better for a civil servant than being the prime minister's PPS." He decided to try his hand at investment banking because he was "impressed by the quality, lucidity and drive" of the bankers he has met.

In keeping with British civil-service rules, the Oxford grad will take a few months off before joining Morgan Stanley. But he won't enjoy the leisurely career pause that most Britons get on their gardening leaves: His wife, Suzanne, gave birth to twins in September. The couple also have a two-year-old son. "That's my free time," he says.