Is Jed Mercurio bored with Line of Duty?

When a drama begins with news of a ‘Chis handler’ receiving ‘intel graded A1 on the matrix’ that causes a ‘conflab with the SFC’, it can mean only one thing: you’re watching a new series of Line of Duty. And just to confirm it, shortly afterwards a bunch of armed police carried out a raid that didn’t go to plan — possibly because it was being led by a bent copper.

As ever, too, there’s a big name playing the potential wrong ’un, with Kelly Macdonald (Trainspotting, No Country for Old Men) guest-starring as DCI Jo Davidson, leader of the Murder Investigation Team. More unexpectedly, Jo’s underlings include Kate Fleming (Vicky McClure), who’s left the anti-corruption unit AC-12 — although maybe not for long, given that Sunday’s episode was largely concerned with getting the old band back together.

Its other two members, admittedly, didn’t start off in great shape. Following hints in the last series that he mightn’t be the toweringly moral figure we’d always imagined, Ted Hastings (Adrian Dunbar) was just about hanging on at AC-12, while also sulking about not being invited to top-level meetings any more. His lieutenant — trusty or otherwise — Steve Arnott (Martin Compston) was reduced to investigating minor irregularities in expense accounts, pausing only to ingest prescription drugs with a level of needfulness rarely seen on TV since the demise of House.

But no sooner had Steve lamented that ‘I’m bored, I need a new challenge’ than he got one, when PC Farida Jatri (Anneika Rose) reported her worries about her boss Jo. That armed raid had been on the flat of a suspect in the inescapably Jill Dando-like murder of a celebrity journalist. On the way, however, Jo stopped the high-speed convoy after she somehow spotted a van down a side street and decided an armed robbery was in progress — which indeed it was, although a suspiciously rubbish one.