In a plan that is clearly long-established and coldly calculated, Tony blackmails an old college classmate with a criminal bent into being his semi-willing assistant. He threatens exposure of his past crimes along with the bait of a large cash payment and secures someone to do the deed while Tony is busy establishing an air-tight alibi. The plan is thoughtful, cautious, executed with care, and runs into serious problems. It is a Hitchcock film, after all.