Mark Bonnar (Colin Osborne) & Jordan Long (DS Murray Boulting) also worked together on New Blood (2016) as Peter Mayhew & Jerry Clarke respectively.
Holly Aird (Elise) & Tom Mannion (Mark Roberts) also worked together on episode 4.4, False Flag: Part 2 (2004), of Waking the Dead (2000) as Dr. Frankie Wharton & Douglas Prince respectively.
Holly Aird (Elise) & Nigel Lindsay (Tom Kelsey) also worked together on Dressing for Breakfast (1995) as Carla & Dave respectively.
Mark Bonnar (Colin Osborne) & Adeel Akhtar (Hassan Mahmoud) also worked together on Apple Tree Yard (2017) as Gary Carmichael & Jaspreet respectively.
Nicola Walker (DCI Cassie Stuart) and Adeel Akhtar (Hassan Mahmoud) previously starred together in River (2015), as Jackie 'Stevie' Stevenson & Ira King respectively.