Booth was getting ahead of his story. He went back to Monday afternoon. At that point the police hadn't been sure what they were dealing with, whether murder, or death by natural causes. It would depend on the pathologist's report, which wouldn't be available until later. As for the items missing from the cabinet, they didn't know yet whether these had been stolen or whether Mrs Troy had removed them herself for some reason. Booth had gone back to Folkestone for the night, intending to return to Rudd's Cross the following day to question the inhabitants.
'I found the station had had a call that afternoon from a firm of solicitors. One of their employees was missing, a man called Biggs. He'd gone out to Rudd's Cross on Saturday to attend to some business for Mrs Troy, who was a client of the firm. For the second Saturday running, apparently. What she wanted was for him to get rid of Grail. After his first visit he reported he'd left a letter giving the fellow his marching orders and he'd volunteered to go back the following week to see him off the property.'
'Kind of him,' Madden observed drily. 'You thought it might have been Biggs who lifted the silver?'
'That was a possible explanation, sir. In a sense it still is. Biggs was supposed to meet a friend in Folkestone on Saturday evening, but never showed up, and no one's seen hide nor hair of him since. Nor any sign of the silver.' Booth blew his horn to warn a couple on a tandem cycle ahead of their approach. The road was narrowing. 'But it strikes me as being farfetched.
If Biggs stole the silver it must mean he smothered Mrs Troy first. But he hardly seems the type. Solicitor's clerk, no record with us. I'm inclined to think he ran foul of Grail.'
Billy, in the back seat, wet his lips. He glanced at Madden, but the inspector's face showed no expression.
Booth continued his story. On arriving at the station the following morning he discovered that the pathologist had confirmed the initial diagnosis. Mrs Troy had died from asphyxiation. Saliva traces on the pillow confirmed his finding. The case was now a murder inquiry and Booth was dispatched to Rudd's Cross with a forensic team. While the others were busy examining the cottage, he had gone from house to house questioning the inhabitants.
'That's when I began to think there was something off about this Grail. No one had seen him close up. A few times he'd been spotted in the fields, coming or going, but apart from the fact that he was reckoned to be a big bloke, no one could say what he really looked like. It made me wonder. I decided to take another look at that shed.'
Booth paused while he turned off the paved surface on to a narrow dirt track that ran between apple orchards where pickers armed with the same type of straw baskets Billy had noticed earlier were busy under the laden trees. A girl with her hair bound up in a red scarf waved to him and Billy tipped his hat and smiled back.
'I'd opened the side door the day before, but there was another door at the front, stable-type, top and bottom, also padlocked. I went to work on that and got it open. I'd only seen the inside in semi-darkness before — the window was boarded over. It wasn't until I had both doors open and light flooding into the place that I saw how clean it was.'
'Clean?' Madden glanced at the sergeant. They were travelling slowly now, easing over the ruts in the lane.
Billy saw a cottage ahead of them, on the right.
'Spotless, sir.' Booth returned the inspector's look.
'Someone had swept and washed the floor until there wasn't a speck of dirt or dust to be seen. But having the light shining in like that made all the difference.'
He grinned. 'I saw something. It was right in the middle of the floor.' He nodded as they drew up beside the house. 'This is Mrs Troy's cottage. You'll see what I mean in a moment.'
They climbed from the car. Booth opened a gate in a hedge and led the way into a small garden. It was well-tended, Billy noticed, the flower-beds weeded and the edges of the lawn trimmed. The sound of the gate squeaking on its hinges had brought a uniformed policeman around from the other side of the thatched cottage. He touched his helmet.
'All quiet, Constable?'
'Yes, Sarge.'
'We've finished with the house for the time being,'
Booth told Madden. 'But I thought it best to leave a man here. We may need to look at that shed more closely'
The wooden structure occupied a corner of the garden. The metal latch hung loosely by a single screw.
'Let's look at it now,' the inspector said.
Booth opened the door and they followed him inside. Though the day was cool the air felt warm and smelled musty under the corrugated-iron roof. Billy made out the dim shape of a work-table at the back of the shed. A fork and a spade stood propped against the wall beside it. Then the room brightened as the sergeant pushed open the double doors at the far end, first the top leaf, then the bottom. Billy peered down at the floor. It was made of cement and looked white and clean, just as Booth had said. He didn't see the mark until the sergeant pointed it out to them.
'It's very faint, sir. But you can just see the outline.'
Billy picked it up then. It was like a shadow on the pale surface. Madden got down on his hands and knees. He peered at the floor closely, then put his nose close to the cement and sniffed.
'I tried to pick out some of the stuff with the point of a knife.' Booth bent over him. 'I'm not sure if there was enough to test.' He shrugged. 'Anyway, I sent it off to the government chemist last night. Don't know when we'll hear from him.'
Madden rose to his feet. He looked at the open doorway at the end of the shed.
'Too narrow for a car,' he observed.
'That's what I thought.' Booth mopped his face with a handkerchief. The fresh air coming in from outside smelled of apples. 'So if that was a patch of oil before he cleaned it up, seems to me it could only have come from a motorcycle standing there.'
Madden grunted. It was hard to tell what he thought.
'And there's something else, sir.' Booth was grinning now, like a conjuror displaying his best trick. 'It wasn't till the idea of a motorbike came into my mind that I thought to look for it. We'll have to go back up the lane a way.'
He led Madden out of the shed and they walked past the parked car and along the dirt track. Billy, following a few paces behind, spied something ahead of them at the side of the road. When they got closer he saw that a shallow depression in the surface had been marked off with a triangle of wooden stakes, tied together with string. A piece of cardboard fixed to one of the stakes bore a rough pencilled message: police notice — keep off. He had missed it when they drove by.
Booth was speaking to the inspector. 'This lane we're on is used by farmworkers to get to the fields and orchards. The only cottage it passes is Mrs Troy's.
It doesn't go anywhere.'
They were standing by the stakes now. The depression held a filling of crusted mud marked with a criss-cross pattern. Booth crouched down, and Madden and Billy did the same. The sergeant pointed with his finger. 'I took a plaster cast of that yesterday afternoon. When I got back to Folkestone I checked it against our book of tyre patterns. It's a standard Dunlop diamond design supplied to motorcycle manufacturers, Harley and Triumph in particular. Someone's ridden a motorbike down this lane in the last few weeks, since the rains started.'
Still Madden said nothing.
'I didn't get the pattern checked till late.' Booth took out a packet of cigarettes and offered one to the inspector, who declined, with a slight shake of his head. 'Chief Inspector Mulrooney had gone home, but I called round to see him and we had a word. I told him what I thought. We wondered if we shouldn't wait for the chemist's report…' Booth pulled a face.
T didn't like the idea of dragging you down here for nothing, sir. Not with what you've got on your hands.