Slow Horses finale leaves River Cartwright collapsing from suspected Novichok poisoning moments after his reunion with Sid

Head writer Gaby Chiappe refuses to say whether River survives: 'People survive it, but people also die from it.' Jack Lowden's spy is struck down at his late grandfather's house while Sid Baker showers upstairs, oblivious. Russian assassins Jim and Jane had visited the property earlier in the season. In Mick Herron's novels, River survives the attack but is left with lasting damage.

Emma Flyte is executed on a beach by Hugo Weaving's hitman Frank Harkness.

Ruth Bradley spent a week playing a corpse: 'I was silently weeping.'

Lowden is widely rumoured to be the next James Bond, fuelling talk of River's exit.