Before leaving Canal Reach, he walked across to number 9, unlocked the door, and turned on the wall switch immediately to his left. But clearly the electricity had been disconnected, and he decided that his nerves were in no fit state to look around the empty, darkened house. On the mat he saw a cheap brown envelope, with the name and address of Anne Scott typed behind the cellophane window. A bill, no doubt, that probably wouldn't be settled for a few months yet-if at all. Morse picked it up and put it in his jacket pocket.

He drove along Canal Street and found himself facing the green gates of Lucy's Iron Works, where he turned right and followed Juxon Street up to the top. As he waited to turn left into the main thoroughfare of Walton Street, his eyes casually noticed the signs and plaques on the new buildings there: The Residents' Welfare Club; The Jericho Testing Laboratories; Welsh & Cohen, Dentists… Yet still nothing clicked in his mind.

Lewis was already back from Abingdon. He had seen Celia Richards alone at the house, and Morse glanced cursorily through her statement.

'Get it typed, Lewis. There are three "r"s in "corroborate", and it's an "e" in the middle of "desperate". And make sure you've got the address right.'

Lewis said nothing. Spelling, as he knew, was not his strongest suit.

'How much exactly did that new rod of Jackson's cost?' asked Morse suddenly.

'I didn't ask, sir. These modern ones are very light, sort of hollow-but they're very strong, I think.'

'I asked you how much it cost-not what a bloody miracle it was!'

Lewis had often seen Morse in this mood before-snappy and irritable. It usually meant the chief was cross with himself about something; usually, too, it meant that it wasn't going to be long before his mind leaped prodigiously into the dark and hit, as often as not, upon some strange and startling truth.

Later that same evening Conrad Richards drove his brother Charles to Gatwick Airport. The plane was subject to no delay, either technical or operational, and at 9.30 p.m. Charles Richards took his seat in a British Airways DC 10-bound for Madrid.

The next morning, two box files, the one red and the other green, lay on the desk at Kidlington, marked 'Anne Scott' and 'George Jackson' respectively. They remained unopened as Morse sat contemplating the task before him. He felt it most unlikely that he was going to discover many more significant pieces to the puzzle posed by the deaths of two persons separated only by a few yards in a mean little street in Jericho. That the two deaths were connected, however, he had no doubt at all; and the fact that the precise connection was still eluding him augured ill for the cheerful Lewis who entered the office at 8.45 a.m.

'What's the programme today, then, sir?'

Morse pointed to the box files. 'It'll probably not do us any harm to find out what sort of a cock-up Bell and his boys made of things.'

Lewis nodded, and sat down opposite the chief. 'Which one do we start with?'

Morse appeared to ponder the simple question earnestly as he stared out at the fleet of police vehicles in the yard. 'Pardon?'

'I said, which one do we start with, sir?'

'How the bloody hell do I know, man? Use a bit of initiative, for Christ's sake!'

Lewis pulled the red file towards him, and began his slow and industrious survey of the documents in the Scott case. Morse, too, after what seemed an inordinately prolonged survey of the Fords and BMWs, reluctantly reached for the green file and dumped the meagre pile of papers on to his blotting-pad.

For half an hour neither of them spoke.

'Why do you think she killed herself?' asked Morse suddenly.

'Expecting a baby, wasn't she.'

'Bit thin, don't you reckon? It's not difficult to get rid of babies these days. Like shelling peas.'

'It'd still upset a lot of people.'

'Do you think she knew she was pregnant?'

'She'd have a jolly good idea-between ten to twelve weeks gone, it says here.'

'Mm.'

'Well, I know my missus did, sir.'

'Did she?'

'She wasn't exactly sure, of course, until she went to the, you know, the ante-natal clinic.'

'What do they do there?'

'I'm not sure, really. They take a urine specimen or something, and then the laboratory boys sort of squirt something-'

But Morse was listening no longer. His face was alight with an inner glow, and he whistled softly before jumping to his feet and shaking Lewis vigorously by the shoulders.

'You-are-a-bloody-genius, my son!'

'Really?' replied an uncomprehending Lewis.

'Find it! It's there somewhere. That plastic envelope with a couple of bits of burnt paper in it!'

Lewis looked at the evidence, the 'ICH' and the 'RAT', and he wondered what cosmic discovery he had inadvertently stumbled upon.

'I passed the place yesterday, Lewis! Yesterday! And still I behave like a moron with a vacuum between the ears! Don't you see? It's part of a letterheading: the JerICHo Testing LaboRATories! Ring 'em up quick, Lewis, and offer to take 'em a specimen in!'

'I don't quite see-'

'They tested her, don't you understand? And then they wrote and-'

'But we knew she was having a baby. And so did she, like as not.'

'Ye-es.' For a few seconds Morse's excitement seemed on the wane, and he sat down once again. 'But if they wrote to her the day before she- Lewis! Ring up the Post Office and ask 'em what time they deliver the mail in Jericho. You see, if-'

'It'll be about quarter to eight-eightish.'

'You think?' asked More, rather weakly.

'I'll ring if you want, sir, but-'

'Ten to twelve weeks! How long has Charles Richards been in Abingdon?'

'I don't think there's anything about that here-'

'Three months, Lewis! I'm sure of it. Just ring him up, will you, and ask-'

'If you'd come off the boil a minute, sir, I might have a chance, mightn't I? You want me to ring up these three-'

'Yes. Straight away!'

'Which one shall I ring first?'

'Use a bit of bl-' But Morse stopped in mid-sentence and smiled beatifically. 'Whichever, my dear Lewis, seems to you the most appropriate. And even if you ring 'em up in some cock-eyed order, I don't think it'll matter a monkey's!'

He was still smiling sweetly as Lewis reached for the phone. The old brain was really working again, he knew that, and he reached happily for the documents once more. It was the start he'd been waiting for.

Within half an hour, Lewis's trio of tasks had been completed. Anne Scott had called at the Jericho Testing Laboratories on the afternoon of Monday, 1^st October, to ask if there was any news and she had been told that as soon as the report was through a letter would be in the post-which it had been on Tuesday, 2^nd October: pregnancy was confirmed. The Jericho post was delivered somewhat variably, but during the week in question almost all letters would have been delivered by 8:30 a.m. Only with the Richards' query had Lewis experienced any difficulty. No reply from Charles's private residence; and at the business number, a long delay before the call was transferred to Conrad Richards, the junior partner, who informed Lewis that the company had indeed moved to Abingdon about three months ago: to be exact, twelve weeks and four days.