Tense drama series about the different challenges faced by the British Security Service as they work against the clock to safeguard the nation. The title is a popular colloquialism for spies, and the series follows the work of a group of MI5 officers based at the service's Thames House headquarters, in a highly secure suite of offices known as The Grid.
Is this the best episode?
The peak run. Top 40% of seasons by average rating — consecutive, with an average of 9.46.
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Peter Firth
Harry Pearce
Nicola Walker
Ruth Evershed
Max Brown
Dimitri Levendis
Lara Pulver
Erin Watts
William Hope
Jim Coaver
Alex Lanipekun
Ben Kaplan
Geoffrey Streatfeild
Calum Reed
Tom Weston-Jones
Sasha Gavrik
Alice Krige
Elena Gavrik
Jonathan Hyde
Ilya Gavrik
All 86 episodes plotted by IMDb rating
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This may take a moment for shows with many seasons.
6 episodes • 2002Avg: 8.4Valley of Despair
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Thou Shalt Not Kill | May 13, 2002 | 7.2 |
| 2 | Looking After Our Own | May 20, 2002 | 9.0 |
| 3 | One Last Dance | May 27, 2002 | 8.6 |
| 4 | Traitor's Gate | Jun 4, 2002 | 8.2 |
| 5 | The Rose Bed Memoirs | Jun 10, 2002 | 8.4 |
| 6 | The Lesser of Two Evils | Jun 17, 2002 | 8.8 |
10 episodes • 2003Avg: 8.6
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Legitimate Targets | Jun 2, 2003 | 8.6 |
| 2 | Nest of Angels | Jun 9, 2003 | 9.2 |
| 3 | Spiders | Jun 16, 2003 | 8.4 |
| 4 | Blood and Money | Jun 23, 2003 | 8.2 |
| 5 | I Spy Apocalypse | Jul 7, 2003 | 8.8 |
| 6 | Without Incident | Jul 14, 2003 | 8.2 |
| 7 | Clean Skin | Jul 21, 2003 | 8.4 |
| 8 | Strike Force | Jul 28, 2003 | 8.5 |
| 9 | The Seventh Division | Aug 4, 2003 | 8.4 |
| 10 | Smoke and Mirrors | Aug 11, 2003 | 9.2 |
10 episodes • 2004Avg: 8.6
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Project Friendly Fire | Oct 11, 2004 | 9.0 |
| 2 | The Sleeper | Oct 18, 2004 | 8.8 |
| 3 | Who Guards the Guards? | Oct 25, 2004 | 8.0 |
| 4 | A Prayer for My Daughter | Nov 1, 2004 | 8.8 |
| 5 | Love and Death | Nov 8, 2004 | 7.8 |
| 6 | Persephone | Nov 15, 2004 | 8.8 |
| 7 | Outsiders | Nov 22, 2004 | 8.5 |
| 8 | Celebrity | Nov 29, 2004 | 8.8 |
| 9 | Frequently Asked Questions | Dec 6, 2004 | 8.2 |
| 10 | The Suffering of Strangers | Dec 13, 2004 | 9.2 |
10 episodes • 2005Avg: 8.8
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | The Special (1) | Sep 12, 2005 | 8.8 |
| 2 | The Special (2) | Sep 13, 2005 | 9.0 |
| 3 | Divided They Fall | Sep 22, 2005 | 8.2 |
| 4 | Road Trip | Sep 29, 2005 | 9.0 |
| 5 | The Book | Oct 6, 2005 | 8.5 |
| 6 | The Innocent | Oct 13, 2005 | 9.0 |
| 7 | Syria | Oct 20, 2005 | 8.8 |
| 8 | The Russian | Oct 27, 2005 | 8.8 |
| 9 | The Sting | Nov 3, 2005 | 9.0 |
| 10 | Diana | Nov 10, 2005 | 9.0 |
10 episodes • 2006Avg: 8.8
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Gas and Oil (Part 1) | Sep 17, 2006 | 8.6 |
| 2 | Gas and Oil (Part 2) | Sep 17, 2006 | 7.8 |
| 3 | The Cell | Sep 18, 2006 | 9.2 |
| 4 | World Trade | Sep 25, 2006 | 8.5 |
| 5 | The Message | Oct 2, 2006 | 8.8 |
| 6 | Hostage Takers (Part 1) | Oct 9, 2006 | 8.8 |
| 7 | Hostage Takers (Part 2) | Oct 16, 2006 | 9.0 |
| 8 | Agenda | Oct 23, 2006 | 9.5 |
| 9 | The Criminal | Oct 30, 2006 | 9.0 |
| 10 | Aftermath | Nov 13, 2006 | 8.7 |
10 episodes • 2007Avg: 8.8
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | The Virus: Part 1 | Oct 16, 2007 | 9.0 |
| 2 | The Virus: Part 2 | Oct 16, 2007 | 9.0 |
| 3 | The Kidnap | Oct 23, 2007 | 9.0 |
| 4 | The Extremist | Oct 30, 2007 | 9.0 |
| 5 | The Deal | Nov 6, 2007 | 5.2 |
| 6 | The Courier | Nov 13, 2007 | 9.0 |
| 7 | The Broadcast | Nov 20, 2007 | 9.5 |
| 8 | Infiltration | Nov 27, 2007 | 9.3 |
| 9 | Isolated | Dec 4, 2007 | 9.0 |
| 10 | The School | Dec 18, 2007 | 9.5 |
8 episodes • 2008Avg: 9.5Golden Era
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | New Allegiances | Oct 27, 2008 | 9.5 |
| 2 | Split Loyalties | Oct 27, 2008 | 9.5 |
| 3 | The Tip-Off | Oct 28, 2008 | 9.5 |
| 4 | A Chance for Peace | Nov 3, 2008 | 9.5 |
| 5 | On the Brink | Nov 10, 2008 | 9.5 |
| 6 | Accidental Discovery | Nov 17, 2008 | 9.5 |
| 7 | The Mole | Nov 24, 2008 | 9.7 |
| 8 | Nuclear Strike | Dec 8, 2008 | 9.5 |
8 episodes • 2009Avg: 9.4Golden Era
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Uranium | Nov 4, 2009 | 9.5 |
| 2 | Energy | Nov 6, 2009 | 9.5 |
| 3 | Tycoons | Nov 13, 2009 | 9.5 |
| 4 | Nemesis | Nov 20, 2009 | 9.5 |
| 5 | Sudden Death | Nov 27, 2009 | 9.5 |
| 6 | Bankruptcy | Dec 4, 2009 | 8.7 |
| 7 | Start a War | Dec 11, 2009 | 9.5 |
| 8 | Brink of War | Dec 23, 2009 | 9.5 |
8 episodes • 2010Avg: 9.3
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Plymouth | Sep 20, 2010 | 8.3 |
| 2 | Oil Baron | Sep 27, 2010 | 9.5 |
| 3 | Paroxocybin | Oct 4, 2010 | 9.5 |
| 4 | Chinese Prize | Oct 11, 2010 | 8.7 |
| 5 | Hotel Lockdown | Oct 18, 2010 | 9.5 |
| 6 | Cybershell | Oct 25, 2010 | 9.5 |
| 7 | Dead Drop | Nov 1, 2010 | 9.5 |
| 8 | Cat and Mouse | Nov 8, 2010 | 9.5 |
6 episodes • 2011Avg: 9.5
| # | Episode | Air Date | Rating |
|---|---|---|---|
| 1 | Garden Leave | Sep 18, 2011 | 9.5 |
| 2 | Stolen Laptop | Sep 25, 2011 | 9.5 |
| 3 | Dirty Bomb | Oct 2, 2011 | 9.5 |
| 4 | Suicide Bomber | Oct 9, 2011 | 9.5 |
| 5 | Kidnap | Oct 16, 2011 | 9.5 |
| 6 | Deportation | Oct 23, 2011 | 9.7 |
