Fade To Black — Rachel E. Rice

Maximillian Blackstone is used to stress. But he's not used having his wife Alexandre Blackstone disappearing and leaving her children and him.
All Alexandre wanted was a quiet life with her husband, Max, especially after what she had been through lately. When she woke lying in what she believed was her bed, in her home, in her play-room, she thought Max had forgotten to untie her.
When Maximillian Blackstone arrived home from a much needed business trip, he expected to see Alex's beautiful face and body, walk down the stairs, and fall into his arms. He waited and waited. She hadn't been home for a week.
Where is she? He thought.
“Whose bed am I lying in naked with my hands and legs tied to the bedposts?” she whispered into an empty room.
This is the final book in the Blackstone series.