Vigil: 7 questions we have after episode 5

But there are still a number of questions still to be answered going into the final episode – while the end of this week's instalment also left the fate of some key characters rather unclear.

We’ve posed all the big questions we have after Vigil episode five below – read on for a full recap and our theories.

Will Glover survive?

Unfortunately, things aren't looking good on this one. When Glover and Amy headed into the contaminated section of the boat, the coxswain's protective suit caught on something and tore – thus exposing him to the nerve agent. He only became aware of this when it was far too late, and it seems clear that he's had far too much exposure to survive the ordeal – just look at him in those final moments. It will be a shame to see him go – he's been one of the most compelling characters throughout the series, and his downfall comes just after he'd seemingly redeemed himself from his previous transgressions.

How will Amy escape?

OK so this question might be a little presumptuous – but we're assuming that one way or another Amy will escape the ordeal she currently finds herself in, the only question is how. This episode revealed the identity of the Russian spy on board Vigil, and this was confirmed for Amy in the worst possible way when she was removing her protective gear following her mission to the contaminated section of the boat. Not only did Matthew Doward dispose of the evidence she'd retrieved from the scene of Jackie's death, he also knocked her out, placed her inside a narrow container and prepared to drown her. It doesn't look good, but surely someone will come to Amy's rescue? Surely...

Who placed Doward on the boat?

So now we know that Doward is the traitor on board Vigil, and what's more, Jackie had been working for him prior to his arrival in exchange for her son's release from prison. She killed Burke to ensure that Doward was called out as a replacement, and he took over the sabotage mission from there. But the question is, who was responsible for deciding that Doward would be Burke's replacement in the first place? Presumably, it was someone higher up the Navy command who had the power to place him on the boat, and so there's still a suspicion that the conspiracy goes higher.

Did the Russians care much about Burke?

For most of the series, it's been assumed that Burke was killed because he was a whistleblower: he knew the Navy had covered up the scandal at Port Havers, and there was a suspicion he was also on to the fact that the Russians had infiltrated Vigil. But it turns out he was actually killed purely so the submarine could resurface and Doward could enter the boat. Does this mean that everything else about Burke was just a decoy – Jackie and Doward knew they could pin the blame on someone else because so many people on the boat resented Burke, making him the perfect target? Or did the killing actually have a dual purpose? Moreover, will Burke's findings go on to have any greater significance?

Can Kirsten get to Ben Oakley on time?

You have to hand it to Ben Oakley – he played Patrick Cruden like a fiddle in this episode, convincing him that he was about to expose the Russian threat to Vigil and that he needed diplomatic protection to ensure his safety. The thing is, it turns out Ben Oakley was the Russian threat – or at least part of it – and that he had a very clear ulterior motive: proving that the nuclear deterrent is unreliable in order for it to be withdrawn, to the Russian's advantage. It's also now clear that he was very involved in Jade's murder after he became aware that she'd gathered evidence of Peter Inglis meeting with his Navy source. Kirsten and her team now have a race against time in order to reach Oakley – can they get there?

Can the Vigil crew make it safely back to land?

There's no two ways about it, Vigil is in a very precarious situation just now. Not only is the boat in the process of being sabotaged, with large parts of it now a no-go zone, but the submarine is now also apparently surrounded by multiple Russian vessels. It's going to be a tough ask for the boat to make it back to land, but will they manage?

Will there be another big twist?

Over the course of Vigil's first five episodes, there have been plenty of outlandish twists and turns so far – and so it would not be a surprise for there to be one more big one to look forward to in the series closer. We certainly hope so...

Vigil concludes on Sunday 26th September at 9pm on BBC One and BBC iPlayer. For more to watch, check out more of our Drama coverage or visit our TV Guide to see what’s on tonight.