Linwood Barclay 
Tap on the Window [EPUB ebook] 

It’s been two months since private investigator Cal Weaver’s teenage son, Scott, died in a tragic drug-related accident. Ever since, he and his wife have drifted apart, fracturing a once-normal life. Cal is mired in grief he can’t move past. And maybe that has clouded his judgment. Because he made a grave mistake driving home on a very rainy night. A drenched young girl tapped on his window as he sat at a stoplight and asked for a ride. And even though he knew a forty-something man picking up a teenage hitchhiker is a fool, he let her in the car–she was the same age as Scott and maybe she could help him find the dealer who sold his son the drugs that killed him. However, after a brief stop at a roadside diner, Cal senses that something’s not right with the girl or the situation. But it’s too late. He’s already involved. Soon Cal finds himself mired in a nightmare of pain and suspicion. Something is horribly wrong in the small town of Griffon in Upstate New York. There are too many secrets, too many lies. And Cal decides to expose those secrets one by one.