passage: Amateur tennis star Guy Haines wants to divorce his vulgar and unfaithful wife Miriam , so he can marry the elegant and beautiful Anne Morton , daughter of a senator .
  While on a train to meet Miriam , Haines meets Bruno Anthony , a forward stranger who recognizes Guy from gossip items in the newspapers that detail his marital problems .
  During lunch in Bruno 's compartment , Bruno tells Guy about his idea for the perfect ` ` Criss - cross '' murder : he will kill Miriam and in exchange , Guy will kill Bruno 's father .
  Since both are strangers , otherwise unconnected , there is no identifiable motive for the crimes , Bruno contends , hence no suspicion .
  Guy hurriedly leaves the compartment but leaves Bruno thinking he has agreed to the deal .
  Guy accidentally leaves his cigarette lighter behind , a gift from Anne to Guy , Which Bruno pockets .
  Bruno heads to Guy 's hometown of Metcalf and follows Miriam and her two beaux to an amusement park , where he briefly illuminates her face with Guy 's lighter , then strangles her to death .
  Guy 's problems begin when his alibi an inebriated college professor on the same train as Guy can not remember their meeting .
  But they increase exponentially when Bruno makes repeated appearances into Guy 's life as he seeks to remind Guy that he is now obliged to kill Bruno 's father , according to the bargain he thinks they struck on the train .
  Bruno sends Guy the keys to his house , a map to his father 's room , and a pistol .
  Soon after , Bruno appears at a party at Senator Morton 's house and hobnobs with the guests , much to Guy 's apprehension and Anne 's increasing suspicion .
query_and_answer: The guy hurriedly leaves the compartment but leaves Bruno thinking he has agreed to the deal . what does he accidentally leave behind || Cigarette lighter
evidences: Guy hurriedly leaves the compartment but leaves Bruno thinking he has agreed to the deal . Guy accidentally leaves his cigarette lighter behind , a gift from Anne to Guy , Which Bruno pockets .