Determined to conquer a lifetime of shyness, Harriet Knight challenges herself to do one thing a day in December that scares her, including celebrating Christmas without her family. But when dog walker Harriet meets her newest client, exuberant spaniel Madi, she adds an extra challenge to her list-dealing with Madi's temporary dog sitter, gruff doctor Ethan Black, and their very unexpected chemistry. Ethan thought he was used to chaos, until he met Madi-how can one tiny dog cause such mayhem? To Ethan, the solution is simple-he will pay Harriet to share his New York apartment and provide twenty-four-hour care. But there's nothing simple about how Harriet makes him feel. Ethan's kisses make Harriet shine brighter than the stars over moonlit Manhattan. But when his dog-sitting duties are over and Harriet returns to her own home, will she dare to take the biggest challenge of all-letting Ethan know he has her heart for life, not just for Christmas?