"Cicadas" are legendary embedded in British society, meant to lie dormant for years before being "activated". While most at MI5 consider them a myth invented by a Russian spymaster, Lamb suspects Bough was telling the truth. The Slow Horses at Work The team begins a fragmented but urgent investigation: Slow Horses - Season 2 Episode 1 "Last Stop" Recap & Review

Bough decides to tail the man across London, following him from a train station onto a rail replacement bus. During the ride, Bough realizes he is in trouble; he appears to suffer a panic attack and frantically types a single word into his phone: . When the bus reaches its final stop, the driver finds Bough dead in his seat, apparently of a heart attack. Jackson Lamb Investigates

The story begins with , a retired field agent who now runs a sex shop in Soho. During a downpour, he spots a man outside his shop who triggers a traumatic memory of being kidnapped and tortured decades ago.