An idea was forming in his mind – an idea which he shrank from and yet could not wholly escape.

In vain he argued with himself that his thought was preposterous and absurd; as the days went on and the whole affair sank more and more into its true perspective, the more the insidious theory grew upon him and began to haunt his nights as well as his days.

At last, very unwillingly, he gave way to his suspicions and set out to test his theory.

His procedure was somewhat erratic. He spent the best part of a week in the reading-room of the British Museum; this was followed by a period of seclusion in his own library, with occasional descents upon the bookshops of Charing Cross Road, and then, as though his capacity for the tedium of a subject in which he was not naturally interested was not satiated, he spent an entire week-end in the Kensington house of his uncle, Sir Dorrington Wynne, one-time Professor of Archaeology in the University of Oxford, a man whose conversation never left the subject of his researches.

Another day or so at the British Museum completed Abbershaw’s investigations, and one evening found him driving down Whitehall in the direction of the Abbey, his face paler than usual, and his eyes troubled.

He went slowly, as if loth to reach his destination, and when a little later he pulled up outside a block of flats, he remained for some time at the wheel, staring moodily before him. Every moment the task he had set himself became more and more nauseous.

Eventually, he left the car, and mounting the carpeted stairs of the old Queen Anne house walked slowly up to the first floor.

A man-servant admitted him, and within three minutes he was seated before a spacious fire-place in Wyatt Petrie’s library.

The room expressed its owner’s personality. Its taste was perfect but a little academic, a little strict. It was an ascetic room. The walls were pale-coloured and hung sparsely with etchings and engravings – a Goya, two or three moderns, and a tiny Rembrandt. There were books everywhere, but tidily, neatly kept, and a single hanging in one corner, a dully burning splash of old Venetian embroidery.

Wyatt seemed quietly pleased to see him. He sat down on the other side of the hearth and produced cigars and Benedictine.