Timing was everything. If he made his move too early, the detective might find himself isolated and he was no match for four armed men and their leader. If he left his intervention too late, a nightwatchman could be knocked unconscious. Keedy had to hope that Marmion and the others were at hand to come to his aid but he saw no sign of them. He began to fear that they’d been shaken off by the lorry as it twisted and turned through the docks.

The leader gave the order and Gill set off, ambling along and puffing at a cigarette. When he saw the light in the gatehouse, he paused to wave to the man inside. After a few moments, the nightwatchman pushed the window ajar so that he could hear Gill. They got into conversation. The barber was relaxed and unthreatening. He was so plausible that the nightwatchman was eventually tempted to open the door. Gill reached in his pocket for the cigarettes. It was the moment that Keedy had been waiting for and he sprang into life.

‘It’s a trick!’ he yelled, running towards the gatehouse. ‘Get back inside and lock the door.’

The man was baffled at first. When he saw Gill pull out the cosh, however, he didn’t hesitate. Leaping back into the safety of the gatehouse, he locked the door and pressed the bell to alert his colleagues in the warehouse. Keedy, meanwhile, had tackled Gill with such power that he bowled him over and forced him to drop his weapon. Thompson was enraged at the betrayal. He charged after Keedy with his cosh held high but he got nowhere near him. Two detectives suddenly came out of the shadows to overpower him, relieve him of his weapon and, in spite of his frantic struggles, put handcuffs on him. Thompson was soon lying face down on the pavement with Gill beside him, also securely handcuffed.

The remaining two detectives used surprise to advantage, coming out of nowhere to take on other members of the gang. The older man was easily arrested and deprived of his weapon but the younger one was much stronger and put up a fight. Keedy had to lend a hand to subdue him. The leader had been quick to gauge the situation. When he heard Keedy shout his warning and saw five men emerge from hiding to attack them, he realised that it was futile to resist. They’d soon have to contend with four nightwatchmen as well. The odds were impossible. The leader therefore discarded the cans of petrol and took to his heels.

Harvey Marmion was after him at once. Having seen the group approaching in the gloom, he’d picked out the leader from the way that he was conveying his orders with gestures. When the man fled, Marmion ran in pursuit, their footsteps echoing along the empty streets. The leader was obviously heading for the lorry. Marmion had to reach him before he could start the vehicle. Pushing himself to the limit, he tried to ignore the burning sensation in his lungs and the jabbing pain in his legs. He was determined to get his man.

The leader heard the footsteps getting closer. When he reached the lorry, he swung round and saw Marmion haring towards him. There was no time to escape in the lorry. Instead he grabbed the starting handle and held it up menacingly. It made the detective slow to a walking pace.

‘I’m Detective Inspector Marmion of Scotland Yard,’ he said, panting, ‘and I’ve come to place you under arrest. The new member who joined the True British League the other night was my colleague, Sergeant Keedy.’

‘Stand back,’ warned the man, waving the starting handle.

‘Put that down, sir — there’s no way out.’

‘At least I can spill a little blood before I’m caught.’

As Marmion came to a halt, two of his men sprinted around the corner to help him. They slowed down when they saw what was happening. On a command from Marmion, the detectives fanned out so that they formed a semicircle around the leader. With his back to the lorry and three detectives in front of him, the man seemed to give up. The hand with the weapon dropped to his side and he sagged in defeat. Marmion wasn’t fooled. As he stepped forward to arrest him, he knew that the man would resist. When the inspector got close, the leader suddenly lashed at him with the starting handle. Anticipating the move, Marmion ducked beneath the weapon, diving into his midriff and slamming him hard against the front of the lorry. The other detectives moved in quickly to overpower the man and hold him while Marmion snapped on the handcuffs. He took a close look at the leader of the organisation. The dungarees and flat cap suggested a workman but his face belonged to a different class altogether.

‘Are you the leader of the True British League?’ asked Marmion.

The man was defiant. ‘I’m proud to hold that title.’

‘Your loathsome organisation has just been dissolved.’

‘Not before we had our triumphs.’

‘Was one of them in Jermyn Street, by any chance?’

‘Yes, Inspector — we burnt some Jews out of business.’

‘Who put you up to it?’

‘Somebody who hates them for what they’ve done to this country and who believes in our mission to drive out the scum.’

‘It was the same man who sponsored tonight’s attack,’ said Keedy, joining them with one hand on the shoulder of a forlorn Gill. ‘According to Ernie here, they were paid by someone to set fire to the synagogue and to destroy Mr Stone’s car.’

Marmion rounded on the leader. ‘Who was your paymaster?’

‘I don’t know, Inspector,’ replied the man.

‘He’s as guilty as you are. Do you want to take the rap while he goes free? That seems very unfair on you. Who is he?’

‘God knows.’

‘He must have a name.’

‘He never told me what it was.’ Marmion looked sceptical. ‘That’s the truth, I swear it. He just handed over money and gave us orders. We enjoyed working for him because he thought like us.’

‘Tell us something about him,’ urged Keedy.

‘Yes,’ added Marmion. ‘How old was he? What did he look like? How did he dress? Describe his voice. Was he a Londoner?’

‘Oh no,’ said the man. ‘He came from somewhere up North.’

The telephone call transformed him. When he came back into the room, Herbert Stone was actually beaming. Ruth and her mother were astonished by the dramatic change in his demeanour.

‘What’s happened?’ asked Miriam.

‘One of my warehouses was going to be burnt down,’ he said, ‘but the police foiled the attack. They’ve caught the men responsible. Inspector Marmion has finally got something right.’

‘That is good news, Herman.’

‘I want all the details. You’ll have to excuse me while I drive over there. Goodnight, Ruth.’

‘Goodnight, Uncle Herman.’

Miriam went out to see her brother-in-law off and left Ruth alone. Something had been puzzling her ever since she’d got back from her visit to the West End. She’d spent hours racking her brain for an answer that would simply not materialise. As she tried to solve the mystery once again, she thought of the figure she’d seen in profile at the end of the alley. Though there was something familiar about his outline, she still couldn’t place him. It wasn’t a close acquaintance but someone she’d met only briefly. Ruth went through a list of names in her head but none of them fitted the man in the alley.

Her mother came back into the room, smiling for the first time since the murder of her husband. Miriam was buoyed up by the news that arrests had finally been made.

‘It’s taken such a load off my mind,’ she said with relief.

Ruth was too preoccupied to hear her. As she concentrated hard on the problem that had been vexing her, a light gradually illumined the figure in the dark alley.

‘I know who it was now, Mummy,’ she cried in delight. ‘The man who watched me last night was Mr Burridge!’

Cyril Burridge and his son had dined in style at the Cafe Royal. As it had been a special celebration, no expense had been spared. Because of the nature of the celebration, Burridge’s wife had been excluded. She was quite unaware of what her husband and son had done. They, however, were savouring their success.