Gone by Lisa Gardner

Pierce Quincy is a former FBI profiler reluctantly separated from his ex-law enforcement wife Rainie. She is an alcoholic who is having a hard time processing a brutal murder case the two had been working on. One night when she can't sleep, she heads out for a drive--and vanishes. Then a troubled foster kid she had been working with also vanishes. Quincy is frantic as he tries to help law enforcement track down his wife. In addition to being bound, gagged, and blindfolded, Rainie is going through withdrawal symptoms from an antidepressant. Gone is a real nail-biter of a book.