Line of Duty's DCI Roz Huntley is having a terrible week at work

Got a stressful week at work coming up? Look on the bright side - at least you're not Roz

The final few seconds in Line of Duty's opening episode showed Tim (Jason Watkins) hovering over DCI Roz Huntley (Thandie Newton)'s lifeless body with a chainsaw.

Then she opened her eyes.

'WHAAAAAT?!' we all yelled in unison from our sofas.

We had to wait until the following Sunday night to discover how that particular cliffhanger panned out. And even then we were only given a partial picture. Rather than a bloody altercation in Tim's flat, Line of Duty's second episode opened the following morning with the discovery of a body in the woods and Roz's office sitting ominously empty. But then she arrived late to work with the excuse of a bad stomach. Tim, not Roz, was dead.

How Roz managed to overpower Tim, particularly given their positioning (her on the floor, him standing over her) at the close of episode one, we still don't know. We know (or assume) she's killed him and attempted to remove her DNA from under his fingernails by chopping three of them off with the chainsaw (ouch).

After establishing Roz was alive, most of episode two saw us follow her in an increasingly stressful, working week from hell track-covering dash between forensics department fridges and Tim's apartment, where we saw her insist - despite protests from AC-12's Steve - on taking over the investigation into a murder she had just committed.

One of the biggest sick-panic moments in the episode for Roz is when she spots a sample of her own blood in Tim's apartment. Before she can sweep it away the sample is swabbed by the forensics team and filed as KRG-13. Before they can discover this is her own blood Roz swaps the sample with some of Tim's blood taken from clothing of his that she's keeping in the boot of her car. But in her panic Roz mishears the number and puts KRG-30 on the plastic packet. Will this little error come back on her later in the series? Most likely.

At the end of episode two we discover that Tim's DNA has been found on the remains of Leonie - one of the women who was murdered by the 'balaclava man.' Was this planted by Roz? Most likely, given she suspiciously asked Rupal to re-examine the evidence, despite having been taken off 'Operation Trapdoor.' This makes the job of AC-12 even harder since they were relying on Tim's evidence against Roz before he was bumped off.

There are other big questions which need answering after episode 2: Is Roz's husband dodgy? Is Farmer guilty? Why is Supt. Hastings being such a chauvinist?

Line of Duty doesn't make for relaxing viewing, but at least watching Roz scrambling to cover her tracks puts the old Sunday night jitters into perspective. However stressful your working week is looking, at least you're not a DCI in charge of an investigation into a murder you've just committed. Because that would be stressful.

Line of Duty is on Sunday night, 9pm, on BBC One