In The Sleepwalker, a new novel by Chris Bohjalian (The Guest Room),  Annalee Ahlberg, a woman prone to walking in her sleep,  has gone missing from her home.  When searchers find a swatch of fabric from her nightshirt,  police conclude that Annalee is dead.  But her oldest daughter, Liana, is puzzled by unanswered questions.  Not to mention the continued attention of a police detective who seems to know quite a bit about her mother.   Harlan Coben calls The Sleepwalker  “a wrenching novel of family secrets and the enigmas that link couples and lovers”