Red Eye ending explained: Who is behind the murders?

The six-part drama is airing weekly on ITV1, but fans also have the option of binge-watching the entire thing as a box set on ITVX – and if that's what you've chosen to do, you may have some questions about the breathless series finale.

Read on for our spoiler-filled summary of the Red Eye ending, including who is responsible for the show's numerous murders and the shocking secret that Dr Nolan has been hiding.

Red Eye ending explained: Who is behind the murders?

Red Eye kicks off with the death of a Chinese woman named Shen Zhao (Elaine Tan), who Dr Matthew Nolan encounters during a business trip to Beijing – but viewers may be surprised to see just how much further the body count climbs.

Alas, the extradition flight that follows proves deadly for Dr Nolan's associates, with suspicion flying in all directions – including his own, as (supposed) air marshal Toni Zhang (Dan Li) questions whether the accused is merely covering their tracks.

However, in the second half of the drama, it becomes increasingly clear that the doctor is being framed, as he initially suggested, with the culprits being from a nation allied to the UK.

Indeed, Mike Maxwell (Mido Hamada) and his fellow CIA operatives were revealed as the masterminds behind Shen Zhao's murder, having cornered the woman in an alley while attempting to retrieve incriminating information she held.

They didn't act alone, however, having planted two mercenaries on the flight back to Beijing, who had been working together to pick off Nolan's friends and witnesses one-by-one.

The most shocking of these is Zhang, who had only been masquerading as an air marshal, while secretly being in cahoots with the silent assassin in the plane's belly and secret compartments.

What was Dr Matthew Nolan given in Beijing?

In a gruesome sequence in the fifth episode, it's revealed that Dr Nolan was given something to smuggle back to the UK by Shen Zhao, with the item in question being a nano SIM card hidden deep inside his stab wound.

To the shock of Madeline Delaney, it is revealed that this had all been part of an MI6 project known as Operation Blindside, in which unsuspecting civilians would be slipped items of dangerous significance to covertly transport to the UK.

Nolan was merely the latest unwitting accomplice in this high-risk strategy, which Delaney's smug colleague John Tennant assured had been successful and undetected up until this point.

In this case, however, the USA was determined to retrieve the asset as it incriminated their own security service in a plot to drive a wedge between the UK and China.

Earlier in the series, it had been mentioned that a Chinese firm was planning to build nuclear power stations in the UK, which ultimately proves central to solving the mystery of the series.

The SIM card contained a remote access programme, supposedly written by the Chinese military to make them capable of sending the reactors of said power stations into catastrophic meltdown.

However, the code had actually been designed by the United States, effectively framing China in order to spook UK authorities out of their energy deal with the East Asian nation – which currently has a somewhat frosty relationship with Washington.

Having unravelled the web of lies devised by agent Mike Maxwell, the series ends with Hana, Dr Nolan and Delaney cooperating with Chinese authorities to lure the rogue operative into their embassy - thus ensuring he will face justice.

However, Delaney stops short of sharing with China the entirety of the devious plan that the CIA had dreamt up, as she seeks to avoid causing a major international incident.

Red Eye is available to stream on ITVX.

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