If you didn’t already know that new BBC drama Vigil was made by the same people as Line Of Duty, you probably could have worked it out eight minutes into the first episode on Sunday night. 

In the same way Jed Mercurio’s hit cop show has become famed for, a major Vigil character was unexpectedly killed off early on – and it was a face that Line Of Duty fans will have found very familiar, too. 

Despite being a much-publicised casting, Martin Compston – better known as DS Steve Arnott – was killed off within the first 10 minutes, as his character Chief Petty Officer Craig Burke was found dead under suspicious circumstances aboard the HMS Vigil.

Enter Suranne Jones’ DCI Amy Silva, who was sent to investigate his death while staying aboard the submarine. 

It quickly became apparent that there’s a lot to unpack following Burke’s death – not least his connections to a peace group campaigning against trident missiles – leaving us with many questions to be answered as the investigation began…

Why was Burke’s body not taken off the submarine?

Silva was told it was “too late” for Burke’s body to be taken off the boat as the hatch closed, despite it previously being agreed that it would be taken to be examined. 

This now means a full post mortem cannot be carried out, and the fact there has been a clear operation to keep his body on board suggests that more than one person could be involved in his death. 

Was Jade really Burke’s girlfriend?

Following her arrest for attempting to break into Burke’s room in the accommodation block, she claimed that she’d obtained his keys as she was his girlfriend.

However, it felt rather convenient when she said no-one else knew about their relationship as they “wouldn’t have been happy”. She also didn’t seem particularly emotionally distraught that her supposed “boyfriend” had just died. 

Could it be that she’d just met Burke through her campaigning as part of the Dunloch Peace Corp, and had been drilling for the information he clearly had?

What happened to Silva’s family?

After experiencing claustrophobia in her bunk, a flashback appeared to suggest Silva’s partner Ian and their daughter were in a car accident that saw them plunged into water. Did they lose their lives? And does this suggest Silva isn’t perhaps the best person to be on board a literal submarine right now?

Why did Silva give up medical school? 

She didn’t answer when Dr Doherty asked. Is this to do with the past trauma in her family?

Why did Hadlow go to see Burke before he died?

Hadlow was one of the last people to see Burke alive and was also the person who found him dead in his bunk. However, questions were raised about exactly why Hadlow had gone to disturb Burke in the first place. 

Were they in on some sort of conspiracy together? Or perhaps he was going to confront him about what Burke been up to in the bomb shop?

Which submarine pulled the Mairi Finnea down? And why?

It was claimed that the Mairi Finnea trawler was pulled down by an enemy submarine, something Vigil captain Paterson Joseph is keen to keep secret, as it would expose the fact they have “always been at war”.

Was Burke killed for risking exposing the truth? After all, we now know that he was about to expose corruption within the British Navy. Speaking of which…

What exactly was Burke’s plan?

The USB that DS Longacre found in Burke’s room had a pre-recorded video message from Burke on it, which he made in case of his death, hinting he anticipated the possibility of being killed for exposing the corruption and fear within the Vigil crew. 

In it, he speaks of “20 different ways to kill Vigil crew single handed” – was he actually going to kill someone before he met his own end?

If the Vigil’s mission is to “stay hidden”, how come Silva was allowed on board?

The boat must have taken a serious security risk to come up to the surface to allow Silva aboard, so does that suggest Captain Joseph was lying about the crew’s mission to “stay hidden”?

Who killed Burke?

At this point in time, there looks to be a number of possible suspects in Burke’s murder – not least Hadlow, Glover, Prentice and even Captain Joesph. 

But with this being a six-part series, something tells us we’re not about to get a definitive answer any time soon…

Vigil continues on Monday at 9pm on BBC One.