AC-12 suspect a cover-up as an officer on DCI Davidson's team appears to have sabotaged the inquiry into Gail Vella's murder.

Cast: Ace Bhatti, Nigel Boyle, Shalom Brune-Franklin, Martin Compston, Amy De Bhrún, Adrian Dunbar, Rosa Escoda, Perry Fitzpatrick, Kelly Macdonald, Vicky McClure, Andi Osho, Prasanna Puwanarajah, Anneika Rose, Michael Yare