Sandilands and the sergeant watched in astonishment as Doris nodded, calmly linked arms with the constable and hurried him into the charge room.

Lily returned to the desk, fire in her eyes. ‘She has four children under the age of six left at home by themselves. She was out earning some cash for their dinner. Her mother would normally look in on the nippers but she’s down with the flu and no one else knows they’re there. The smallest is only nine months old and will be screaming with hunger by now. The oldest is only five and can’t control the toddlers. I’ve promised to go round and stir up a neighbour who might be persuaded to lend a hand. It’ll take about an hour. Will you excuse me, sir?’

She was turning for the door in her eagerness to be off. Sandilands grabbed her by the shoulder. ‘No, I won’t excuse you,’ he said firmly. He fixed the sergeant with a flinty glare. ‘Constable Wentworth is assisting me on a matter of national importance. I will not have her precious time wasted doing social work arising from the incompetence of desk staff.’ He produced a ten-shilling note from his pocket and handed it to the sergeant. ‘Give the woman this and set her loose. You should have more sense than to allow the premises to be cluttered up by trivial, time-wasting cases at a moment of emergency.’

‘Yessir. At once, sir.’ The sergeant followed the pair into the charge room, leaving the door open, handed the note over with a flourish and in a few words explained that Doris was to be bailed immediately, orders of the commander.

As Doris ran off with a backward wave and a mouthed ‘Ta, love!’ for Lily, the sergeant turned again to Sandilands. ‘Wonderful, sir. Glad you called by. Now, would the constable like to deal with Rob Roy in the tam-o’-shanter over there? He’s been making his way back to Loch Lomond for the last two hours.’

‘What’s the charge?’ Sandilands asked.

‘Drunk and disorderly. Could have been grievous bodily harm if we’d been able to make one of the complainants stand and testify. Drunk as a skunk. Caught making lewd gestures with his sporran and assaulting any man he heard talking English in Leicester Square. And that takes a bit of doing nowadays but he managed to find and clobber six before we got hold of him. Down here with his mates for a wedding and got left behind. Officer Smithson who’s grammar school educated and knows what he’s talking about says it’s a Celtic custom. All to do with … stag-worship, I believe he said. The horned god … fecundity … plenty of drink taken … that sort of thing.’

‘I don’t think the Scots need to refer to the calendar before they plan a knees-up. And the many-antlered Cernunnos would hardly recognize our friend as an acolyte,’ Joe added since the sergeant seemed to be partial to a bit of northern folklore. ‘Lord! Let’s hope our chap isn’t the bridegroom. What’s his name?’

‘Doesn’t remember his name or his address. Thick accent – we can’t work out a word he’s saying.’

Sandilands put a hand on Lily’s arm. ‘My turn, I think, Wentworth. You have his belongings, sarge?’

The officer produced a shoe box from under the counter. ‘No calling card, I’m afraid, sir, to give us a clue. Let’s see what we have got.’ He muddled through the items, listing them one by one. ‘Just a small amount of cash, a couple of beer mats, a map of London, a used handkerchief, a ticket stub and a sporranful of confetti.’

Joe held back a flash of impatience as he viewed the contents of the box. These clowns had all they needed to hand and had ignored it. He pounced on the ticket. ‘It doesn’t exactly have his address on it, but this ticket was issued in Glasgow. He came down on a return ticket and this is the all-important return half. What time is the next train to Scotland from King’s Cross?’

‘One every hour, on the half-hour, I think.’ The response was subdued as the sergeant took account of the lapse. He hung his head, waiting for the inevitable reprimand.

It didn’t come. The commander’s tone was encouraging. ‘Right. Then our problems are over. There’s one in twenty minutes. Send one of your blokes with him in a taxi to the station. He’s to be sure to put him on the train and watch him disappear.’ He took out another ten-shilling note. ‘This is for the taxi and any other expenses. Now give him his belongings back and get him out of here.’ He looked about him as the sergeant saw to it and commented drily: ‘Not sure I can afford to know you lot much longer.’

‘Peace and quiet comes at a price around here,’ murmured the sergeant.

‘I’m already enjoying my quid’s worth,’ Joe replied as the great door swung closed and everyone listened in relief to nothing but the distant hum of traffic on Piccadilly.

‘Now, to business,’ he went on. ‘Constable Wentworth wishes to cast an eye on the pair arrested in connection with the shooting of Admiral Dedham last night. You still have them here? I left instructions that they were to be handed on to no one else. Come on, man! You have them?’

The sergeant replied with surprise and reluctance. ‘Yes. Yes. Of course, sir. In the cells.’ He leaned across the counter in a show of confidentiality. ‘Not that we haven’t had offers from other interested parties to take them off our hands, just like you warned us. I stonewalled ’em, of course. Referred them to you, sir. Seemed to work. But, sir, er … Not sure the prisoners are fit to be interviewed in the presence of a lady officer. Rough types. They resisted arrest, of course. And they’ve had an intensive interrogation. They’re resting at present. Getting ready for their day in court. Preliminary hearing at the Old Bailey. No one’s wasting much time over this, eh, sir? Knotting the rope already, you might say …’

Sandilands cut him short. ‘We’ll go through. Five minutes for each man. No more. You are holding them in separate cells?’

‘That’s right, sir. Watch out for the big one. He’s a nasty piece of work. The little ’un’s got no more fight in him. He’ll give no trouble.’ He summoned up a brute-faced copper with hands like ham shanks. ‘PC Kent has established relations of a sort with them. He’s got their number. Kent – take them through to see our Irish friends, will you? And watch out for the lady. And, sir, we’re saying five minutes, tops, with each. If Constable Wentworth can take as much as five minutes.’

They followed Kent through one of the six doors that gave access to the cells. After a great deal of flourishing with the keys and clanging of bolts, Joe entered a step ahead of Lily into the cell of the larger and more aggressive of the two prisoners.

The stench made him reel back. The small space stank of urine, blood, vomit and a disturbing chemical smell that made him retch. The gloom was disorienting. Somewhere in that fetid darkness a form moved slightly and uttered a groan. Focusing on the sound, Joe eventually made out the shape of a man sitting uncomfortably on a narrow metal bench. He was hunched over, clutching his stomach, and paid no attention to their entrance. Was this the assassin? It could have been anyone. His head was sheathed from chin to scalp in a thick layer of bloodstained surgical bandage. Someone had cut a hole around the nose and mouth to allow him to breathe.

With a gesture, Sandilands indicated to Lily that he was allowing her precedence and stood back a pace. Trying to keep her voice level, Lily introduced herself to this nightmare figure and asked: ‘Sean, will you show me your back, please?’

The figure growled and shrank further into the wall.

‘You’ll get no cooperation from him, miss,’ said Kent who was standing protectively at her side. ‘Bullet’s out if that’s what you’re bothered about. Taken away for evidence. The doc had to put him out cold to extract it. Ether it was, to get him to be still. That’s what you can smell. He’s been patched up good and proper. They’ll take him to the hospital when he’s heard his charges.’