Simon ignored him. “Let’s imagine for a minute that they had: Melissa drives from her home in Highgate to Nicki’s in Spilling to pick Nicki up. At least a two-hour drive. Then together they drive to Grantham, which is half an hour from Spilling. Then back to Spilling after the auction to drop Nicki off, and then Melissa drives back to Highgate—two longer journeys and two short ones. Instead, what happened was that Nicki drove to Highgate to pick Melissa up, then to Grantham, then back to Highgate to drop Melissa off, and then Nicki drove back to Spilling. Four long journeys, instead of two long and two short. Eight hours’ driving—eight hours!—when it could have been only five. As a plan, that makes no sense, unless Nicki has a phobia of being driven by anyone but herself. And, I think, her husband,” Simon added as an afterthought. “He’s probably the only one she’ll agree to be driven by. He drove her to the train station last Tuesday, when she wanted to go to London to see Melissa and couldn’t take her own car because we needed to inspect its side mirror, or lack of.”

“You offered her a lift home after we interviewed her,” said Sam. “She refused.”

“Didn’t want to be driven by us,” Simon said. “She had no choice when we turned up at her house and insisted she accompany us to the police station, which was why she was such a hysterical mess at first. Partly why, at any rate. So she refused a lift home and set off running instead. She’d told us she had other things to do in town, but I followed her. Instead of heading toward the shops, or going to the taxi rank by the Corn Exchange and getting a cab, she ran in the direction of her house. It couldn’t have been lack of cash. There’s an ATM opposite the Corn Exchange.”

“The train to London,” said Sam. He appeared to be too startled by what he’d realized to say anything else.

Simon knew what he meant. “Yes, the trains that were supposedly not running on Tuesday afternoon, forcing Nicki to rent a car. I checked: the trains on Tuesday ran exactly according to the schedule—no problems at all. But Nicki didn’t want to travel by train because of her phobia, so she had her husband drop her at the station, then walked to a car-rental place.”

“Her husband doesn’t know about her phobia?” Gibbs asked.