Character timelines

Gary Oldman · Series 1–5

Jackson Lamb

1. Series 1 · Desk chief revealedApparent indifference gives way to decisive protection of the team.
2. Series 2 · Old scoresCold War knowledge becomes operational leverage.
3. Series 3 · Parallel rescueHe pursues Standish while the team fights through the records facility.
4. Series 4 · Harkness confrontationHe turns a private operator’s contingency planning against him.
5. Series 5 · Destabilisation patternHe reads apparently separate crises as one coordinated design.

Jack Lowden · Series 1–5

River Cartwright

1. Series 1 · ExileA failed training exercise sends an ambitious agent to Slough House.

1. Series 2 · Upshott coverHe works alone inside a suspected sleeper operation.
2. Series 3 · Park breachA timed theft tests his loyalty and judgement.
3. Series 4 · Family filePrivate history becomes part of intelligence history.
4. Series 5 · Changed responsibilitiesHe works with the personal consequences of the Cartwright revelations.

Kristin Scott Thomas · Series 1–5

Diana Taverner

1. Series 1 · Off-book pressureHer attempt to control an operation puts her in direct conflict with Lamb.
2. Series 2 · Institutional survivalShe contains damage while competing agendas move around the Park.
3. Series 3 · FootprintSuppression of damaging evidence becomes the institutional struggle.
4. Series 4 · Cold-body crisisShe manages a threat rooted in Service history.
5. Series 5 · Political terrainShe navigates destabilisation and leadership friction.

Saskia Reeves · Series 1–5

Catherine Standish

1. Series 1 · Office anchorHer competence quietly holds Slough House together.

1. Series 2 · Old loyaltyHer history with Charles Partner explains part of Lamb’s protectiveness.
2. Series 3 · Targeted abductionA tiger-team operation weaponises guilt and memory.
3. Series 4 · Cartwright protectionShe joins David’s fragile support network.
4. Series 5 · Independent loyaltyHer connection to the team outlasts a job description.

Rosalind Eleazar · Series 1–5

Louisa Guy

1. Series 1 · PartnershipHer work with Min helps the office begin acting like a team.

1. Series 2 · Permanent lossA surveillance failure has consequences she cannot compartmentalise.
2. Series 3 · Records facilityShe joins River inside the operation’s most dangerous ground.
3. Series 4–5 · Experienced operatorGrief and competence coexist without cancelling either.

Aimee-Ffion Edwards · Series 2–5

Shirley Dander

1. Series 2 · ArrivalTechnical ability and volatility arrive together.

1. Series 3 · Unauthorised rescueShe and Marcus choose the fight at the records facility.
2. Series 4 · Pressure testImpulse and loyalty remain strengths and risks.
3. Series 5 · Life after MarcusLoss changes her aggression and attachment to the desk.

Kadiff Kirwan · Series 2–4

Marcus Longridge

1. Series 2 · Experienced arrivalCalm field presence is complicated by private gambling.

1. Series 3 · Operational partnershipHe and Shirley enter the records-facility siege.
2. Series 4 · Final operationCourage and compulsion converge during the Harkness crisis.

Christopher Chung · Series 1–5

Roddy Ho

1. Series 1 · Technical gatekeeperHe mistakes specialist access for universal superiority.

1. Series 2–3 · Remote operatorHis screens make him essential even when his judgement is not.
2. Series 4 · Unchanged self-imageEvents change around him faster than his view of himself.
3. Series 5 · Manufactured intimacyHis private life becomes an entry point into a public operation.

Olivia Cooke · Series 1 and confirmed Series 6 return

Sid Baker

1. Series 1 · More than another slow horseHer surveillance role conceals a more complicated assignment.
2. Series 1 · Unresolved exitViolence at Slough House leaves her immediate future uncertain.

1. Series 6 · Official returnApple confirms Sid Baker’s return but does not establish episode outcomes. Official announcement ↗

Jonathan Pryce · Series 1–5

David Cartwright

1. Series 1 · The Old BastardRiver’s grandfather is introduced as a formidable retired Service figure.

1. Series 2 · Cold War targetAn old intelligence grievance reaches his home.
2. Series 4 · Memory and historyDeclining memory collides with a buried operation and River’s family history.
3. Series 5 · After the revelationHis care becomes part of River’s altered personal landscape.

Hugo Weaving · Series 4–5

Frank Harkness

1. Series 4 · Deniable architectThe Westacres investigation exposes the private network he built.
2. Series 4 · Personal connectionRiver learns why Harkness is more than an operational adversary.
3. Series 5 · Continuing leverageThe consequences of his methods extend beyond one confrontation.