to light," said
Whiteside. "I've got the car here, sir, and we might discuss it on the
way back to the Yard."

"What is it?" asked Tarling.

"We got it from Mr. Lyne's manservant," said the inspector. "It appears
that the butler had been going through Mr. Lyne's things, acting on
instructions from headquarters, and in a corner of his writing-desk a
telegram was discovered. I'll show it you when I get to the Yard. It has
a very important bearing upon the case, and I think may lead us to the
murderer."

On the word "telegram" Tarling felt mechanically in his pockets for the
wire which Mrs. Rider had given him from her daughter. Now he took it out
and read it again. It had been handed in at the General Post Office at
nine o'clock exactly.

"That's extraordinary, sir," Detective-Inspector Whiteside, sitting by
his side, had overlooked the wire.

"What is extraordinary?" asked Tarling with an air of surprise.

"I happened to see the signature to that wire--'Odette,' isn't it?" said
the Scotland Yard man.

"Yes," nodded Tarling. "Why? What is there extraordinary in that?"

"Well, sir," said Whiteside, "it's something of a coincidence that the
telegram which was found in Mr. Lyne's desk, and making an appointment
with him at a certain flat in the Edgware Road, was also signed 'Odette,'
and," he bent forward, looking at the wire still in the astonished
Tarling's hand, "and," he said in triumph, "it was handed in exactly at
the same time as that!"

An examination of the telegram at Scotland Yard left no doubt in the
detective's mind that Whiteside had spoken nothing but the truth. An
urgent message was despatched to the General Post Office, and in two
hours the original telegrams were before him. They were both written in
the same hand. The first to her mother, saying that she could not come;
the second to Lyne, running:

"Will you see me at my flat to-night at eleven o'clock? ODETTE
RIDER."

Tarling's heart sank within him. This amazing news was stunning. It was
impossible, impossible, he told himself again and again, that this girl
could have killed Lyne. Suppose she had? Where had they met? Had they
gone driving together, and had she shot him in making the circuit of the
Park? But why should he be wearing list slippers? Why should his coat be
off, and why should the night-dress be bound round and round his body?

He thought the matter out, but the more he thought the more puzzled he
became. It was a