“Can’t you see why?” said Mr Sandbach, patronizingly.  “He’s afraid of the bookstall clerk catching him at it.  He’s afraid it’s the bookstall clerk that has dropped that half-sovereign.  You wait till the bookstall clerk finishes those papers and goes inside, and you’ll see.”

At this point Mr Gale made the happy involuntary movement of a man who has suddenly thought of something really brilliant.

“Look here,” said he.  “You said you’d bet.  But you didn’t bet.  I’ll bet you a level half-crown I get him to shift this time.”

“But you mustn’t say anything to him.”

“No—­of course not.”

“Very well, I’ll bet you.”

Mr Gale walked straight up to the shabby man, drew half-a-sovereign from his waistcoat pocket, and held it out.  At the same time he pointed to the shabby man’s boots, and then in the most unmistakable way he pointed to the exit of the platform.  He said nothing, but his gestures were expressive, and what they clearly expressed was:  “I know you’ve got a half-sovereign under your foot; here’s another half-sovereign for you to clear off and ask no questions.”

Meanwhile the ingenious offerer of the half-sovereign was meditating thus:  “I give half-a-sovereign, but I shall gather up the other half-sovereign, and I shall also win my bet.  Net result:  Half-a-crown to the good.”

The shabby man, who could not have been a fool, comprehended at once, accepted the half-sovereign, and moved leisurely away—­not, however, without glancing at the ground which his feet had covered.  The result of the scrutiny evidently much surprised him, as it surprised, in a degree equally violent, both Mr Gale and Mr Sandbach.  For there was no sign of half-a-sovereign under the feet of the shabby man.  There was not even nine and elevenpence there.

Mr Gale looked up very angry and Mr Sandbach looked very foolish.

“This is all very well,” Mr Gale exploded in tones low and fierce.  “But I call it a swindle.”  And he walked, with an undecided, longing, shrinking air, in the wake of the shabby man who had pocketed his half-sovereign.

“I’m sure I saw him put his foot on it,” said Mr Sandbach in defence of himself (meaning, of course, the other half-sovereign), “and I’ve never taken my eyes off him.”

“Well, then, how do you explain it?”

“I don’t explain it,” said Mr Sandbach.

“I think some explanation is due to me,” said Mr Gale, with a peculiar and dangerous intonation.  “If this is your notion of a practical joke.”

“There was no practical joke about it at all,” Mr Sandbach protested.  “If the half-sovereign has disappeared it’s not my fault.  I made a bet with you, and I’ve lost it.  Here’s your half-crown.”

He produced two-and-six, which Mr Gale accepted, though he had a strange impulse to decline it with an air of offended pride.

“I’m still seven-and-six out,” said Mr Gale.