It's amazing how something so grim, and filmed in mostly bleak surroundings can be so entertaining.
It was gripping and very well done. Bring on Series 3, but as others have mentioned, what major crimes will Catherine have to solve then? Poor woman must be totally traumatised, given she has stumbled across so many dead bodies and been 'lead copper' in solving all the mysteries in the area. It's no wonder she doesn't move her lips when she speaks - she must be exhausted.
It would be rather nice to see her smiling, letting her hair down and enjoying family life for a change, but would she lose something by becoming a smiley, middle aged woman? She never worries about buying bread, what's for dinner, doing the Lottery, putting her feet up in front of the telly with a bottle of wine, etc. I know she had a night out with colleagues but she had to be drunk before she loosened up. She seems to be on-call all the time, even when she's not. She and her sister always have 'serious' conversations too. Poor Ryan. Never mind his Dad, he's likely to be badly affected later by the down in the mouth, preoccupied, older women in his life who never seem to do cuddles or happy bedtimes.
I suppose if the writer gave her more facets/dimensions the general darkness of the series would be lost. (Oh and when I discuss this with others we have to remind ourselves it's only TV drama! )