Death Angel - The Angel Series, #5

With help from a mysterious caretaker and a forgotten friend, Stevie barely escapes death. Val wants to rekindle their relationship, but Stephanie has unresolved issues with him, and questions his loyalty. They have to put their problems aside when they discover that Dom and Jeffery are held captive in the Shadow Sphere: a dark, gloomy land inhabited by ghouls. Time is of the essence. Val and Stephanie must rescue their friends before they vanish to another dimension, and are lost forever.
When Stephanie discovers a secret about Aidan, everything changes. Can Stephanie and Val save Dom and Jeffery in time, and will Stephanie rekindle her love with Val, or will she find her way back to Aidan?