Gillard sprinted back towards the main building, and just outside reception almost collided with the very officer he wanted. PC Tiana Clore – a tough Barbadian, built like Serena Williams – had represented Barbados in the heptathlon in the London Olympics and could run the 200 metres in twenty-one seconds. He explained who they were looking for and said that he was going up to the roof. He asked her to cover the grounds until the dog team arrived. The female receptionist, overhearing him, said she would see if the drone team was nearby. Two other PCs volunteered to help. One, a fresh-faced male recruit called Davies, headed up to the roof with Gillard while the other joined Tiana Clore.

Four flights of stairs later, the detective chief inspector burst out onto the flat roof. He felt this would have been too high for Zayan Lal to have reached from the refectory block, but it gave a perfect view down onto all the other buildings in the police campus. Gillard made his way past the twelve rows of angled solar panels to look down into the partially enclosed rear gardens while Davies peered across to the front over the car park and into the wooded grounds. For a moment, neither of them saw anything unusual. Then Gillard, looking south at the original Mount Browne house, spotted a figure huddled in a shadow between two gables. Lal had ditched the white kitchen apron, leaving dark shirt and trousers. He was crouching like a gargoyle, focusing below on officers assembling with dogs in the car park. He showed no signs of having spotted Gillard on the higher roof.

The detective called Davies over and pointed out their quarry’s position. The gothic-style, three-storey, red brick building was a perfect hiding place, with its many steep pitched roofs, Victorian chimney stacks and mullioned windows. Davies couldn’t at first see the figure within the shadow, until Gillard pointed him out.

‘Keep an eye on him while I go down. Call me if he moves,’ Gillard said. The detective then ran back to the stairs, descended and calling PC Clore to join him made his way over to the historic building. At the reception desk Gillard asked the security man about the various staircases which gave access to the roof. There were three. One was always locked, and a second was a fire escape. Gillard chose the third, the main maintenance access, whose door gave out onto a small piece of flat roof behind a low battlement. He opened it carefully.

The fugitive was just ten feet away on the next gable. He gradually stood up as the detective emerged, a smile widening across his face. The only way around to Lal was by clambering on the steep moss-encrusted slates to the right which connected the two gables. To the left, it was at least fifty feet down to the concrete.

‘Don’t make this difficult for yourself,’ Gillard said. ‘You can’t escape.’

‘Come and get me then,’ Lal said, pulling a small but wicked-looking knife from his belt. Gillard could feel the presence of Tina Clore behind him. She had a Taser, but to use it up here would be lethal. The detective edged out onto the roof, steadying himself on the tiles with his right arm, his left out for balance over the cast iron gutter. Ideally he would have preferred to be wearing a pair of trainers like Lal’s for this, but there hadn’t been time to get to his locker. Polished black brogues may look the part but their grip was clearly inadequate.