Line of Duty episode 5 first-look images reveal Jo Davidson and Steve Arnott working together

Various stills released by the BBC show Steve and Jo kitted out in bulletproof jackets, as they appear to be responding to a major incident.

In one of the images, the pair can be seen engaging in dialogue with each other, while another shows them inspecting an unknown target – with Steve wearing a sullen expression and Jo appearing shocked.

Jo's MIT colleague DS Chris Lomax can also be seen in both images, but no other members of AC-12 appear in the stills, nor does Kate Fleming.

Meanwhile, in a third image, Steve can be seen standing by a door alongside an unknown police officer, with his gun drawn – as he appears to be heading into a presumably dangerous situation.

It remains to be seen what has brought Steve and Jo together at this apparent crime scene, but given the dramatic developments of episode four, pretty much nothing is off the table.

At the end of episode four, Macdonald's character appeared to be under even more suspicion than ever from AC-12, after the bombshell discovery of Joanne Davidson's mystery relative.

It will therefore be particularly interesting to watch how things unfold between Jo and Steve, especially given they have already clashed earlier in the season.

That said, the images do appear to show the pair working alongside each other with no obvious signs of friction – perhaps they've been brought together against a common threat?

We'll have to wait until Sunday to find out!

Line of Duty continues on Sundays at 9pm on BBC One. If you’re up to date with the latest season, why not read our Line of Duty episode 4 recap. Take a look at the rest of our Drama coverage, or check out our TV guide to see what’s on TV this week.