He manœuvred the print from its anchorage in the album, and handed it to Grant. He came downstairs with Grant and saw him to the door, talked a little about the little courtyard when Grant admired it, and waited courteously until Grant had reached the gate before closing the door on him.

Grant opened the evening paper that was lying on the car cushions and laid the photograph carefully between its folds. Then he drove down to the river and along the Embankment.

The old place looked very much as usual, he thought, as the hideous pile loomed up in the dusk. And so, too, did the finger-print department once he got there. Cartwright was stubbing out a cigarette in the saucer of a half-drunk cup of cold tea and admiring his latest handiwork: a complete set of left-hand prints.

‘Lovely, ’m?’ he said, looking up as Grant’s shadow fell across him. ‘These are going to hang Pinky Mason.’

‘Hadn’t Pinky the price of a pair of gloves?’

‘Huh! Pinky could have bought up Dents. He just couldn’t believe, clever little man Pinky, that the police would ever get round to thinking it anything but a suicide. Gloves are for small-time trash: burglars and such; not for master-minds like Pinky. You been away?’

‘Yes. I’ve been fishing in the Highlands. If you’re not too busy could you do something off the cuff for me?’

‘Now?’

‘Oh, no. Tomorrow would do.’

Cartwright looked at the clock. ‘I’ve nothing to do till I meet my wife at the theatre. We’re going to Marta Hallard’s new play. So I can do it now, if you like. Is it a difficult job?’