s
cowardly, yet more assertive friend who had tempted him to evil. It was
a good theory; and was held pretty generally, I fancy, even by the
police.

"I say 'even' because they worked really hard in order to build up a
case against young Hatherell, but the great difficulty was that of time.
At the hour when the policeman had seen the two men outside Park Square
together, Walter Hatherell was still sitting in the Harewood Club, which
he never left until twenty minutes to two. Had he wished to waylay and
rob Aaron Cohen he would not have waited surely till the time when
presumably the latter would already have reached home.

"Moreover, twenty minutes was an incredibly short time in which to walk
from Hanover Square to Regent's Park without the chance of cutting
across the squares, to look for a man, whose whereabouts you could not
determine to within twenty yards or so, to have an argument with him,
murder him, and ransack his pockets. And then there was the total
absence of motive."

"But--" said Polly meditatively, for she remembered now that the
Regent's Park murder, as it had been popularly called, was one of those
which had remained as impenetrable a mystery as any other crime had ever
been in the annals of the police.

The man in the corner cocked his funny birdlike head well on one side
and looked at her, highly amused evidently at her perplexity.

"You do not see how that murder was committed?" he asked with a grin.

Polly was bound to admit that she did not.

"If you had happened to have been in Mr. John Ashley's predicament," he
persisted, "you do not see how you could conveniently have done away
with Mr. Aaron Cohen, pocketed his winnings, and then led the police of
your country entirely by the nose, by proving an indisputable _alibi_?"

"I could not arrange conveniently," she retorted, "to be in two
different places half a mile apart at one and the same time."

"No! I quite admit that you could not do this unless you also had a
friend--"

"A friend? But you say--"

"I say that I admired Mr. John Ashley, for his was the head which
planned the whole thing, but he could not have accomplished the
fascinating and terrible drama without the help of willing and able
hands."

"Even then--" she protested.

"Point number one," he began excitedly, fidgeting with his inevitable
piece of string. "John Ashley and his friend Walter Hatherell leave the
club together, and together decide on the plan of campaig