The final episode of not to be missed thriller Apple Tree Yard airs on BBC One on 6 February at 9.00pm.
The murder trial continues, with Costley’s defence resting on evidence of an underlying personality disorder.
But the prosecution barrister rips this theory apart and Costley’s case seems to lie in tatters. Costley’s back is up against the wall. Has he reached his tipping point?
And if the court find out that Yvonne lied about their affair, will they believe anything else she’s said?
Our picture shows Gary Carmichael played by Mark Bonnar.
Apple Tree Yard Episode 4 (of 4) airs on Monday 6 February 2017 from 9.00pm-10.00pm on BBC One.