Magic By Moonlight — Maggie Shayne

When PI M.C. Hammersmith finds herself on the wrong side of a mob boss, she is desperate for protection. So desperate that she goes through an old family spell book and performs a protection spell. But protection arrives in the form of an 18th century musketeer. Chivalrous, and dedicated, Alexandre vows to protect the lady, and in the process finds the one woman who could steal his heart.