ing to his club."

"How was he dressed?" asked Tarling.

"That is rather important," nodded the Commissioner. "For he was
in evening dress until nine o'clock--in fact, until after Stay had
gone--when he changed into the kit in which he was found dead."

Tarling pursed his lips.

"He'd hardly change from evening into day dress to go to his club," he
said.

He left Scotland Yard a little while after this, a much puzzled man. His
first call was at the flat in Edgware Road which Odette Rider occupied.
She was not at home, and the hall porter told him that she had been away
since the afternoon of the previous day. Her letters were to be sent on
to Hertford. He had the address, because it was his business to intercept
the postman and send forward the letters.

"Hillington Grove, Hertford."

Tarling was worried. There was really no reason why he should be, he told
himself, but he was undoubtedly worried. And he was disappointed too. He
felt that, if he could have seen the girl and spoken with her for a few
minutes, he could have completely disassociated her from any suspicion
which might attach. In fact, that she was away from home, that she had
"disappeared" from her flat on the eve of the murder, would be quite
enough, as he knew, to set the official policeman nosing on her trail.

"Do you know whether Miss Rider has friends at Hertford?" he asked the
porter.

"Oh, yes, sir," said the man nodding. "Miss Rider's mother lives there."

Tarling was going, when the man detained him with a remark which switched
his mind back to the murder and filled him with a momentary sense of
hopeless dismay.

"I'm rather glad Miss Rider didn't happen to be in last night, sir," he
said. "Some of the tenants upstairs were making complaints."

"Complaints about what?" asked Tarling, and the man hesitated.

"I suppose you're a friend of the young lady's, aren't you?" and Tarling
nodded.

"Well, it only shows you," said the porter confidentially, "how people
are very often blamed for something they did not do. The tenant in the
next flat is a bit crotchety; he's a musician, and rather deaf. If he
hadn't been deaf, he wouldn't have said that Miss Rider was the cause of
his being wakened up. I suppose it was something that happened outside."

"What did he hear?" asked Tarling quickly, and the porter laughed.

"Well, sir, he thought he heard a shot, and a scream like a woman's. It
woke him up. I should have thought he had dreamt it,