Glenister should be walking a few paces behind, but he dared not turn to look. His train ticket was tucked into the back of his trouser pocket, the holdall was swinging against his knees – he could feel the weight of the metal with each step and his heart was clattering in his chest, surging blood around his body so violently he could feel the pulse in his neck.

Houghton crossed the road, narrowly dodging a cab which sounded its horn more out of irritation than anger, and headed towards the station, walking briskly past a busker tunelessly strumming a battered acoustic guitar. Somewhere behind him, in the heart of the capital, bodies were lying in the gutter, yet here, little more than a mile away, unconcerned shoppers and tourists were throwing coins into a busker’s dirty hat. Bulldog spirit of the Blitz, he told himself. The station, and their escape from the centre of the city, was now just thirty seconds away.

#

At the foot of the majestic white flight of stone steps that led to the entrance of Waterloo station, two armed police stood in Kevlar vests and helmets, their eyes darting around the crowds, trying to pierce through the scarves and hats and coats for someone resembling the picture that had come through on WhatsApp. They held their rifles pointed down, but were ready to take aim if the suspects posed a threat to them or the milling bodies around them.

The younger of the two men scratched his leg. He had dressed quickly that morning and the strap holding his Glock pistol on his thigh was too tight. Getting more comfortable was out of the question, so he continued to scour the faces around him.

#

Houghton was inside the station, a few yards from the stone archway entrance, propped up against one of the red cast-iron pillars that supported the Victorian glazed roof. The crowd in front parted and for a moment he could see an armed police officer, just twenty metres away. He stopped breathing, wondering whether to run or reach into the bag. Time froze – then the police officer walked away. Houghton breathed again, focusing on the air in his lungs, trying to ignore the buzz of adrenaline in his veins. He was just an ordinary person waiting for a train, he told himself.

#

The armed officer swung his head from left to right. Still nothing. And then, a glimpse of someone in the crowd to his left. He turned his head, and his companion sensed his movement. A man in a baseball cap and grey hoodie. White. About the right build as the photo. And with a rucksack. The pair moved forward earnestly, parting the crowds around them. The entrance to Waterloo was too crowded to challenge him, but once the police were on the concourse, there would be more room.

#

The station seemed busier now in front of Houghton. He didn’t dare look around for Glenister, he just kept his head down, kept his back jammed against the iron pillar. Ahead was the platform display board. He checked the train – it was on time and in the station. He would leave it until the last possible moment to run for the train. For now, he just had to wait.