The detectives investigate two murders in which the victims have been placed in water and surrounded by flowers. Vera and sidekick Joe believe the culprit may be linked to a group of bird-watching friends, but despite their increasingly tangled and dysfunctional relationships, the twitchers seem determined to protect one another. Drama adapted from Ann Cleeves' novel Hidden Depths, starring Brenda Blethyn, David Leon, Gina McKee, Wunmi Mosaku, Paul Ritter and Neil Armstrong.