A Study in Amber (1st Book in the Series Holmes and Holmes)
by P. J. Humphrey
In the early 21st century, the ghost of Sherlock Holmes turns up in the San Francisco flat of a young wanna-be detective, Sherry Holmes. His sudden appearance in the old Victorian building doesn’t shock her, since Sherry’s adoptive mother, a B-class Hollywood actress, told her she was a descendant of the fictional detective. But can she solve crimes as he did in the 19th century without his help?