‘Twenty miles exactly, sir, to the end of the drive from Shepherd’s Bush,’ answered Sligo promptly.

‘Right!’

Alleyn packed his case and began with Fox and Sligo to examine the yard and the gateway into the lane.

‘Here are the tracks clear enough in the lane,’ said Fox. ‘We’ve got enough here and more to show this caravan was driven into the lane, backed up to the studio window and loaded up through the window. Who does the caravan belong to?’

‘Miss Troy, I think,’ said Alleyn.

‘Is that so?’ responded Fox, without any particular emphasis.

‘We’ll find out presently. Seal the garage up again, will you, Fox? Blast this weather. We’d better have a look at Pilgrim’s car.’

Basil Pilgrim’s car was a very smart supercharged two-seater. The upholstery smelt definitely of Valmai Seacliff, and one of the sidepockets contained an elaborate set of cosmetics. ‘For running repairs,’ grunted Alleyn. They opened the dicky and found a man’s rather shabby raincoat. Pilgrim’s. ‘Also for running repairs, I should think.’ Alleyn examined it carefully, and sniffed at it. ‘Very powerful scent that young woman uses. I fancy, Fox, that this is the pure young man’s garment for changing wheels and delving in engines. Now then, Sligo, you have a look at this. It’s ideal for demonstration purposes—the sort of thing Holmes and Thorndyke read like a book. Do you know Holmes and Thorndyke? You should. How about giving me a running commentary on an old raincoat?’

Sligo, breathing noisily, took the coat in his enormous hands.

‘Go on,’ said Alleyn; ‘you’re a Yard man, and I’m taking notes for you.’

‘It’s a man’s mackintosh,’ began Sligo. ‘Made by Burberry. Marked “B. Pilgrim” inside collar. It’s mucked up like and stained. Inside of collar a bit greasy, and it’s got white marks, too, on it. Grease on one sleeve. That’s car grease, I reckon, and there’s marks down front. Pockets. Right-hand: A pair of old gloves used, likely, for changing tyres. There’s other marks, too. Reckon he’s done something to battery some time.’

‘Well done,’ said Alleyn. ‘Go on.’

Sligo turned the gloves inside out.

‘Left hand inside got small dark stain on edge of palm under base of little finger. Left-hand pocket: Piece of greasy rag. Box of matches.’ Sligo turned the coat over and over. ‘I can’t see nothing more, sir, except a bit of a hole in right-hand cuff. Burnt by cigarette, likely. That’s all, sir.’

Alleyn shut his notebook.

‘That’s the method,’ he said. ‘But—’ He glanced at his watch. ‘Good Lord, it is eight o’clock. You’d better cut back to the studio or your relief will be giving you a bad mark.’

‘Thank you very much, sir. I’m much obliged, sir. It’s been a fair treat.’

‘That’s all right. Away you go.’

Sligo pounded off.