Secret Service ending explained: Was there a Russian asset in the UK government and if so, who?

*Warning – contains full spoilers for all five episodes of Secret Service.*

All five episodes of new spy thriller Secret Service are now available to watch on ITVX, and they see Gemma Arterton’s MI6 agent, Kate, investigating evidence which points towards a top-flight British politician being a Russian asset.

This all comes as a leadership election is underway within the Labour Party to replace the Prime Minister, with Amaka Okafor’s Imogen Conrad and Mark Stanley’s Ryan Walker being the two most likely candidates.

But, for those who have already got to the end of all five episodes, did one of them turn out to be a Russian asset? And just where did we leave Kate, her husband Stuart (played by Rafe Spall), and the rest of the characters come the end of the season?

Read on for everything you need to know about the ending of Secret Service on ITV.

Who won the leadership election?

In the end, it was Ryan Walker who won the Labour leadership contest, and ultimately became Prime Minister.

A video of Imogen Conrad having sex in a Montenegro hotel with a man who wasn’t her husband was leaked to the press, and it ultimately damaged perception of her enough to mean Ryan pulled ahead.

Kate originally thought that Zak might be the man Imogen had an affair with, who was obscured in the video. In the end, she actually found out that not only was the man obscured, his face had been deepfaked, seemingly to keep his identity a secret.

In the end, she found out why…

Who was the Russian asset in the UK government?

The man in the video having an affair with Imogen, and in the end the Russian asset at the heart of the UK government, was none other than Kate’s own husband, Stuart!

Kate found out because she realised she was in Prague on a trip at the same time that Igor Borodin was. It was on this trip that Borodin recruited Stuart.

Having uncovered the truth, Kate convinced Stuart to join her in Finland, before revealing to him what she knew. They met by the Russian border, where she revealed that she knew he had sex with Imogen in Montenegro.

This video had been presented to Stuart in Prague, and the Russians had agreed to erase him from it in exchange for information.

At first, they had just wanted gossip from Cabinet, but later they had wanted more information about Kate, her job and her movements. The deeper he got into his lies, the less he could pull out and tell the truth.

This doesn’t mean Ryan Walker didn’t have links with Russian oligarchs, reaching right into the heart of the Russian state. He wasn’t the specific asset leaking intel, but he still had the potential to be working for Moscow.

The reason Kate had Stuart meet her by the Russian border is she had decided to let him go, to live in Russia, rather than going on trial for treason in the UK, which their children would have to witness.

What happened to Kate at the end of the season?

In the final scenes of the season, Kate attended Rav’s funeral and spoke with Sir Alan about her plans to leave MI6. She told him she hoped to arrange visiting rights for her children and Stuart in a mutual country, once things had settled down.

She then approached Zak, who said that he wanted her to stay on at SIS, despite her having missed Stuart’s deception. He told her that he needed help to keep an eye on Ryan – revealing he too had doubts about his allegiances.

Kate was seconded to the Cabinet office, to keep an eye on any “hostile influences”. She greeted the new Prime Minister in Downing Street as he took up his position.

Secret Service is available to watch in full now on ITVX.

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