They Never Came Home — Lois Duncan

Dan and Larry's hiking trip ends in a missing persons search. Can Joan find her brother before it's too late?

When high school buddies Larry Drayfus and Dan Cotwell take a backpacking trip into the Mogollon Mountains, nobody is concerned when they don't come home exactly on time. Dan is a natural outdoorsman, and he knows the mountains well. Larry is smart and resourceful. But soon the boys' families must accept the unthinkable, as little sign of them can be found in the hills. For Larry's sister -- and Dan's girlfriend -- Joan, grief soon turns to mystery when some of her brother's old acquaintances start calling with strange and threatening messages. In They Never Came Home, the truth of Larry and Dan's disappearance is far more shocking than any of their loved ones can anticipate.