Both police officers smiled. But there was no humour in their expressions. ‘Can we see upstairs?’ Holly Little asked.

‘Sure. Then after that I’ll give you a tour of the garden – sorry, the grounds – to see if you can find evidence of a freshly dug grave, eh?’ He half smiled.

They carried out their check of the house, then went out into the well-tended garden. The immaculately mowed lawn was lined on either side with a riot of colour. Flowers and shrubs, all weed-free. There was a potting shed and a little wooden summerhouse, both in good condition, sited attractively between two mature fir trees at the far end.

As they walked along, Holly Little observed, a little enviously, ‘Someone has green fingers, what a beautiful garden – all we have in our flat are window boxes.’

‘That’s me,’ Niall said proudly. ‘My hobby – passion. I do all the beds and Eden looks after the lawn.’

Little stopped to admire one dense plant that was chest-high, full of bright-red flowers that were in the shape of long, narrow brushes. Part of one side of it was missing – it looked like it had been broken away. ‘This is stunning!’

‘Callistemon citrinus,’ Niall said. ‘Or in English, a bottlebrush plant. One of my babies. Unfortunately, Eden got rather distracted the other evening when she was mowing the lawn – she said our new mower ran away with her – and she took a chunk out of it.’

‘Will it grow back?’ Alldridge asked.

‘If disease doesn’t set in.’

Both officers noticed the slight anger in his voice as he said it.

He led them out to the front to the bike storage unit and unlocked it. Alldridge and Little scanned inside. Other than a dark pool of dried oil on the floor, it was spotless, a Honda motorbike, a posh road bike and two paddleboards propped against one another.

They went back indoors and sat in the lounge again.

‘Can you think of any reason at all why your wife might not have come back to you in the car park of Tesco yesterday, sir?’ Holly Little asked.

‘No, none. None at all, it makes no sense.’

‘Do you or she have any enemies that you are aware of?’

‘Enemies?’ Niall looked genuinely surprised. ‘No, none – other than her mother.’ Then he quickly added, ‘Joke!’

‘Your mother-in-law?’ Alldridge probed. ‘Is there some animosity between you?’

‘Oh, plenty,’ Niall said with a tinge of bitterness. ‘She always felt her daughter could have done better.’

‘You’re sure your wife isn’t with her now?’ PC Little asked.

‘I told you, I’ve checked with everyone, including all the local hospitals. I’ve had three texts from her mother this morning asking if I have any news of her – want to see them?’

‘If you don’t mind.’

He showed the officers each of them, in turn.

‘Has your wife ever experienced any mental health issues?’ Alldridge asked.

‘Other than she must have been mad to marry me?’ Niall said with a grin that fell from his face as fast as his comment fell flat. ‘No.’