‘She doesn’t run the home, we run it together,’ he said reluctantly.

‘Would you say she would have known when you were critically low of household items – such as cat litter?’

‘Yes, absolutely.’

‘In your opinion, is it likely she could have forgotten that she had any cat litter in your home last Sunday, when she asked you to stop on your way back to buy some?’

Niall took some moments before answering. ‘No, no way.’

‘You are certain?’ Potting said. Playing him as if he were a well-hooked fish.

‘Yes.’

Potting nodded calmly. ‘During the search of your house last night, two large sacks of cat litter were found at the rear of a cupboard, in the utility room off your kitchen. Do you have any explanation for that?’

Paternoster stared back in numb silence for some moments, then he said, ‘I’m sorry, I don’t believe you.’

‘Really?’ Potting said in a commanding performance that brought a faint smile to Exton’s face. ‘So how do you explain that? Do you have any explanation for how they got there or are you saying the police planted two sacks of cat litter in your house?’

Paternoster looked dumbfounded. He stared at his solicitor, then up at the ceiling and around at the walls. ‘Two sacks of litter?’

‘Correct,’ Potting said. ‘Two large sacks of Tesco Lightweight ten-litre cat litter – several weeks’ supply for a normal household cat.’

Paternoster ran his hands through his hair, looking genuinely confused. Then he said, ‘All I can think of is that Eden must have bought the stuff in Tesco after I dropped her off and someone she met in the store drove her home. Or it was there all along but neither of us realized. That can happen, right? You forget you have something in the cupboard – it’s not the strangest thing in the world, is it?’

Jon Exton looked down at a wad of notes in front of him, and leafed through a couple of pages. ‘Niall, I have a copy of a printout of all sacks of cat litter sold in the Tesco Holmbush store between midday, Sunday the first of September, and 4 p.m., when the store closed. There was just one sack purchased, at 1.34 p.m., a time you say you were at Parham House. There were no other sacks purchased that afternoon.’

‘Their computer must be wrong,’ he said flatly.

‘Are you suggesting that the store may have had technical issues on last Sunday afternoon?’ Potting asked. ‘Their CCTV down, perhaps, and their inventory computer system also?’

Paternoster looked down at the floor. ‘If there are two sacks of cat litter in our house, either my wife had a major memory lapse or, yes, the Tesco inventory system must be wrong.’

‘Let’s hypothesize for a moment,’ Potting said. ‘In the event that the Tesco inventory system was working fine, and your wife did not buy any there, are there any other stores where, between 3.15 p.m. and 4 p.m. when all stores close on a Sunday, your wife could have bought two sacks of cat litter? Of the particular brand that Tesco sell? Tesco Lightweight ten-litre sacks?’