Kissed by an Angel by Elizabeth Chandler
The Power of Love
It's 704 pages.
A love beyond life...a danger beyond doubt.
When her boyfriend, Tristan, died, Ivy thought she'd lost everything, even her faith in angels. But now she's discovered that he's her guardian angel -- his presence so strong that she can feel the touch of his hand, the beat of his heart. Ivy needs Tristan now more than ever because he knows she's in terrible danger. Only Ivy's guardian angel can save her now that his killer is after her.
But if Tristan rescues Ivy, his mission on earth will be finished, and he must leave her behind forever. Will saving Ivy mean losing her just when he's finally reached her again?