Don't let go by Harlan Coben

A little quiet town in the States.

A policeman reopens the enquiry of what happened fifteen years ago, when his twin brother was found on the railway tracks, killed by a train, with his girl friend.

And some other friends of those times die....Why? The more he looks for clues, the more the incredible seems to surge. What really happened behind those fences forbidden to the public? 

Pure thriller.