“It ought to be possible for the police to trace where the call came from,” suggested Mr. Ludgrove.

“Of course. The Inspector told me they’d done that already, but it didn’t get them much further. The call came from one of the boxes at Paddington station, one of them automatic contraptions where you press the button when you’re through. If you’re sharp with the button, there’s nothing to tell the people you’re speaking to that you’re speaking from a box. And, of course, at a place like Paddington there’s no one to see who goes in and out of those boxes.”

“I see. And where was Wal Snyder when the call was made?”

“Oh, in the Express Train all right. He’d got his alibi fixed up, no fear of that. Put one of his pals on to that job, the cunning young devil. And then, of course, he’d watch till Jim came past the pub on his way home, and the rest was easy.”