Ep 6. Intelligent Design: Part 2

On the night of his release from prison after a term for causing death by dangerous driving, former Oxford don Richard Seager is himself crushed to death by a car. His last act is to scratch the number 500 into the car's paintwork. Later, the body of a girl is discovered in the attic of the college chapel and identified as Soo-Min Chong, a Korean student who disappeared 15 years earlier. Seager was not scratching the number 500, after all. Lewis, Hathaway and Hobson poke around the new crime scene, watched anxiously by Martha Seager and teacher Carl Drew. Seager the last person to see Soo-Min alive, Carl Drew was her boyfriend and Martha her organ tutor. There are two more deaths while Lewis and Hathaway are trying to close in on the killer.