The Dowager's Wager — Nikki Poppen

Isabella Hartfield has long suspected her marriage of convenience seven years ago to an aging Marquess was the motive for Tristan's sudden military enlistment. For years she has harbored guilt over driving him into danger. Now, she is widowed and Tristan has returned. In an attempt to repair the damage she did years ago, Isabella takes a Valentine's Day wager that she can find Tristan a wife from among the Ton by June, never daring to dream the wife he wants is her. The closer she gets to finding him a bride, the more her heart aches for him.

For seven years Tristan Moreland has lived a double life on the war torn Continent as a secret agent for the Crown in the guise of a womanizing socialite officer. Now he is ready to come home to claim his land, his title and a wife--the love of his youth, Isabella Hartfield.

But before Tristan can lay claim to his happiness and her heart, he must ferret out one last enemy of England who will go to any length to see Tristan dead. When his nemesis makes Isabella a target in order to draw him out, Tristan must choose between protecting his country or his love.