Time's Mirror - Ghosts, Inc., #5

Ghosts, Inc. - where the paranormal is normal!Paranormal researcher Tesla Dane has never known her father.  She doesn't even know who he is!  The only connection she's ever had to him is a huge, gold gilt mirror he once owned where shadows seem to move deep within its silvery surface in the dark of night. So she's more than a little surprised when, one night, a sinfully handsome man emerges from those very shadows - a man who has the power to turn Tesla's world upside down.
Inventor Alexander Hartfield had been working for Tesla's father in a parallel universe since the early 1900s.  But now, The Inventor, as her father is affectionately known, has gone missing.  Alex hopes that by bringing the beautiful Tesla to Avalon, she can coax her father out of hiding - especially since the man has never met the daughter who bears his name.  He also hopes that he can keep his hands off of Tesla.  Because she's the boss' daughter.  And Alex isn't quite who he claims to be.