The kid rounding a corner with a woman in the end of the episode is Cillian Murphy's son.
Tom Hardy (Alfie Solomons) and Charlotte Riley (May Carleton), who are married, are both in this episode but don't share any scenes.
Charlie Murphy (Jessie Eden) & Sophie Rundle (Ada Shelby) also worked together on Happy Valley (2014) as Ann Gallagher & Kirsten McAskill respectively.