The Strangers On The Trains
Emily Watson is a research assistant working at the MOD. She gets a call from asking her to attend a meeting at SIS ( Special Intelligence Services or MI6). She quickly learns that she has been assigned a case involving train crashes going back sixty years. Her remit is to find out who the "strangers" are that seem to be involved in all these "accidents". But everything is not straight forward, she soon discovers that other people have tried to research the case and have all ended up dead.