Drawn to a life of excitement and risk, Lady Millie Aldon made a pact to forsake marriage. But her plans are thrown into chaos when Chase Wentworth returns to town. The lanky lad she remembers from childhood is now the Marquess of Chaselton, possessing an air of mystery Millie can't resist. As Chase moves through London's elite circles, his stealth manner has Millie convinced he harbours a secret—one she is determined to reveal. As Millie makes a game of observing Chase's every move, she finds her attraction to him unsettling. When a stolen kiss threatens to turn their flirtation into something more powerful, she questions her vow of freedom. But Millie has no idea of the danger she's facing. Chase has a complicated past—and his clandestine efforts to expose a traitor will soon provide a more perilous—and passionate—adventure than Millie could ever have planned.