Grace: why tonight's episode confirmed Brighton-based detective series as essential viewing

It feels a long, long time since we had a detective and a city which fitted together so perfectly – just as Morse and Oxford did in the 1980s.

But, at last, it is happening again – with Grace and Brighton proving the best crime double act in more than a generation.

The first TV adaptation of the first of bestselling author Peter James’ Brighton-based Roy Grace detective novels impressed on its debut last year.

But with the second episode last week, there was a huge sense that the whole thing stepped up a gear. The actors actually started to become those characters that we have been reading about across 17 brilliant novels so far; and importantly, we also started to get a genuine sense too of the relationships between them.

Tonight, the Grace series, with its third episode, took maybe its biggest leap so far: the one that fully establishes it as a thrilling series which is now fully into in its stride – a series with the legs to run and run for as long as Peter James is prepared to keep writing the novels.

Did you catch Peter James’ cameo?

And thank goodness, there is no sign of him slowing down. Novel number 18 comes out in the autumn; and episodes four and five will be broadcast next Sunday and the Sunday after. All we have to do is get through this week. The series is now absolutely required Sunday night viewing.

Tonight’s episode was Not Dead Enough, a TV dramatisation of James’ third novel in the series. And it offered a first rate mystery. A body washes up on Brighton beach as Grace jogs by; before long there’s another body, the wife of a wealthy Brighton socialite – and there are reasons to believe he’s the killer.

Except… and this is Peter James’ brilliance… the socialite was most definitely somewhere else.

How can one person be in two places at exactly the same time? That’s the mystery that Roy Grace has got to unravel.

Grace - how John Simm is conquering the TV screen as Peter James’ Brighton detective Roy Grace

But the real significance in this episode is undoubtedly the introduction of pathologist Cleo Morey. Zoe Tapper in the part instantly brings alive the connection which sparks between her and Grace.