George Palmer-Jones met Greg Franks first at Holywell Pond, a Northumberland Wildlife Trust Reserve. The memory of the meeting was strangely vivid, though there had been many such incidents in his birdwatching career. Afterwards, when other rare birds turned up, he looked out for Greg and noticed him. Despite that, when Mr. and Mrs. Franks hired him to trace their missing son, he did not at first connect them with the boy who had disturbed the Baillon’s crake at Holywell. When he did, the memory of the day returned to him sharp and complete, as if it had happened only minutes before.

It had been early June, a hot and sticky day with the threat of thunder and swallows flying low over yellow rape fields. The field by the pond was waist-high with buttercups, clover, and cow parsley. George arrived at the hide overlooking the pond at lunchtime, to discover that the bird had not been seen that day. It was probably skulking in the reed bed, said the exultant locals who had found the bird. It often did that.

The hide was full of people crammed together along the bench seat, waiting. There was the smell of hot creosote and damp vegetation. They talked occasionally, but their attention was on the still water. They were prepared to wait until evening. “Just be patient,” said the locals. “ It came out at dusk yesterday. It won’t have gone anywhere.”

Then Greg Franks burst into the hide. He seemed physically incapable of patience. He paced across the wooden floor smoking one cigarette after another, and his restlessness was so obvious, so flamboyant, that he unsettled all the others there.

“I want some action,” he said at last. “ I’m going in. I need this bird.”

“Don’t be a fool, man,” said one of the locals, a big square man with hands like spades. “You’ll scare it off; then no one will see it. This is a nature reserve. Do you think the trust will put out news of other rarities if you go tramping all over it?”

He stood up to confront Greg, blocking his way, and George thought there might be a fight. But Greg was too quick for them. He slipped out of the hide and into the reserve. They saw his sleek black head moving like a stoat’s through the reed bed. A moorhen gave an alarm call and splashed into view. In the hide there was silence.