Forbidden Legacy. Trinity Masters: Fall of the Grand Master, #4

A man who sacrificed love for duty. The woman he lost. And the one who can bring them together. Harrison Adams has served as leader of the Trinity Masters for a decade, always placing the society above his own needs-even when it comes to the one woman who calls to him. When a dangerous threat surfaces, Harrison sets a plan in motion that could save the organization, but it comes with a price. Alexis turned down an invitation to join the secret society, afraid to relinquish control over her life, her future, and her heart, even though that rejection means she and Harrison are forced to ignore their desires.
She throws herself into her job and her difficult working relationship with her boss, Michael. He's attractive and maddening, but Alexis has zero plans to give in to the crazy chemistry between them. Harrison asks Alexis to experiment in a ménage relationship with him and she agrees, unaware their third will be Michael. She never knew how giving herself to them would inflame her desires. Or how much she would enjoy submitting to them.
But when an evil man looking for revenge sets his sights on Harrison, time is the one thing none of them have. And it soon becomes apparent Harrison's forbidden legacy could destroy them all.