"I want to speak to her," he said. "It's most urgent."

Cavallino spread his hands.

"If you would care to wait, sir, I don't think she can be much longer." He consulted his watch. "It is nearly half-past two. She is not usually as late as this."

"She's not in then?" Don said, his voice sharpening.

"No, she went out soon after twelve-thirty when her friend called for her."

"What friend?"

Cavallino frowned.

"Excuse me, sir, but you ask too many questions. It is not my business..."

"My reason is urgent," Don broke in. "Gina Pasero is connected with Shapiro. He was murdered in her flat and I think she is in danger. Who was the friend who called for her?"

"I don't know," Cavallino said, staring at Don in alarm. "A girl: I haven't seen her before. Miss Pasero returned from the club just after midnight. Someone called her on the telephone. At half-past twelve she came down from her room. I asked her if she were going out, but she acted as if she hadn't heard me. She went out. I went to .the door. There was a car waiting. Miss Pasero was talking to this girl. They got into the car and drove away."

Don hunched his shoulders against the chill that crawled up his spine.

"What was the girl like?" he asked, and the tone of his voice made Cavallino stiffen.

"I couldn't see much of her, but I did notice her hair. It was an unusual colour: a Venetian red."

Don stared at him for a long moment.

"Let me have your telephone," he said curtly Cavallino pushed the telephone towards him.

"There is something wrong then?" he asked anxiously.

"That's what I'm going to find out," Don said and dialled Whitehall 1212.

Lorelli sat in the driver's seat of the Humber, her hands over her ears, her eyes shut.

The old, battered car stood under the trees of the towpath, a few yards from Risings Lock. It was dark, and the white, damp mist hid the river.

It had been too easy. She had traced Gina to the Miremare Hotel. Gina had recognized her at once, although it was now five years since they had met in Siena. She had accepted Lorelli's tale that there was work for her again in Italy. Excited and unsuspicious, she had got into the car to discuss the details.

Crantor had been hiding in the back of the car. He had risen up and hit Gina with a sock filled with wet sand. He had struck her on the top of her head, very hard and viciously. She had slumped against Lorelli. Shuddering, Lorelli had pushed her away from her, and Crantor, leaning over the front seat, had shoved Gina's unconscious body off the seat on to the floor.

"Okay," he said. "Straight ahead. I'll tell you where to go."

It had taken them half an hour to reach Risings Lock. It was now a quarter past one. The towpath was deserted. Crantor got out of the car and stood listening for some moments to the sound of the rain, the gentle movement of the river and the wind in the trees. Then he dragged Gina's body out of the car, letting it slide on to the wet, muddy tarmac.

"Wait for me," he said and picking up the unconscious girl, he threw her over his shoulder and walked away into the darkness.

Lorelli waited, her hands pressed to her ears. She couldn't bear to hear the splash that she knew would follow when Crantor threw Gina into the river. After an interminable time Crantor returned to the car. He was breathing heavily. The front of his dirty trench coat was wet.

"Move over," he said curtly. "I'll drive."

Lorelli slid along the bench seat. Crantor got in under the steering wheel, started the car, turned on the parking lights and drove along the towpath. After a hundred yards or so, he turned left on to the main road.

He drove fast, heading for London. Neither he nor Lorelli said anything until they came to the main London road, then Crantor said abruptly, "What will you do now?"

"The job's finished," Lorelli said. "I'll go back. I'll catch the ten o'clock plane to Rome."

"Is it safe? They'll be watching the airports."

"My papers are in order. They won't recognize me. Of course it's safe."

"Don't be too sure. The cops here are smart."

"They won't worry me."

"You'll tell Felix I did a good job?" Crantor said.

"Yes, I'll tell him," Lorelli said indifferently.

Crantor looked sideways at her.

"You don't sound enthusiastic. It is important he should know how I handled it."

"You were well paid," Lorelli said, staring through the windscreen at the beams of the car's headlights as they raced ahead of them.

Crantor grunted. He drove for ten minutes or so without speaking, then he said, "Do you want to stay at Polsen's for the night?"

"I may as well," she returned.

Again he glanced at her. Then his big, hairy hand dropped on to her trousered knee.

"You and I could be useful to each other," he said.

She hit the back of his hand hard with her handbag. The steel clip cut the skin. He jerked his hand away, cursing.

"Every man I have had to work with comes out with that proposition," Lorelli said angrily. "Can't you be different?"

"Why?" Crantor snarled as he sucked at his bleeding hand. "I'm a man, aren't I? Just because my face..."

"Oh, shut up!" Lorelli snapped. "You flatter yourself. What's your face got to do with it?"

Crantor's hands gripped the steering wheel viciously. He imagined his ringers' were sinking into her white throat.

They drove on in silence.

It wasn't until half-past two the following afternoon that Don came down to his study.

Marian was sitting at his desk, busying herself with a pile of unanswered correspondence. She concealed a smile as she watched him amble to his favourite armchair and lower himself into it with a groan.

"What a night!" he exclaimed, clasping his head in his hands.

"I didn't get to bed until half-past eight this morning. If this goes on much longer I'll finish up in a home for incurables."

"It wasn't so long ago that you told me you didn't need any sleep," Marian said, getting up and coming over with a number of letters in her hand. "Will you see your mail now?"

"Most certainly not!" Don said firmly. "I'm not doing a stroke of work today. Put those letters away and sit down. I want to talk to you."

With a resigned sigh, Marian put the letters on the desk and sat down.

"How's Julia?" Don asked, struggling with a gigantic yawn.

"She's better. The doctor says she can see the police tomorrow, and if she continues to make progress she can go home in a week."

"That's fine. I'm going to offer her the villa at Nice. She shouldn't go back to the Hampstead house after what has happened. The change and sun will do her good. I won't leave London until this murder has been cleared up. Right now, we don't seem to be getting anywhere." He went on to tell Marian what had happened the previous night. "So now Gina has vanished. The police are hunting for her, but they haven't got a thing to go on. Except for the hotel clerk, no one seems to have seen her. This woman with the red hair haunts me. She turns up and vanishes like a ghost."

"Why was Shapiro murdered?" Marian asked.

"The police had his description. He had to keep under cover. d.i.c.ks thinks the gang - he's convinced there is a gang over here decided he was too big a danger, so they wiped him out." He reached for a cigarette and lit it. "I'm hanged if I can see how we are going to get anywhere unless we get a lead on the Tortoise himself. d.i.c.ks thinks he is in Italy, and I'm inclined to agree with him. The facts point to it. He uses an Italian weapon. He only attacks Italians, and the redheaded woman is an Italian. d.i.c.ks wants me to go to Italy and hunt around for information. He has a pathetic faith in my abilities after the Tregarth business. It's a c.o.c.keyed idea.' f can't go tramping over the whole of Italy in the hope of running into the Tortoise. If I could narrow the hunt down to a town or even a district I'd go, but I just don't know where to start."

"I think Siena would be a good starting place," Marian said.

Don stared at her.

"Siena? Why Siena of all places?"

"I've been doing some research," Marian said quietly. "You told me you couldn't understand why this extortioner calls himself the Tortoise, and that there must be a reason. I began going through books on history and symbolism, trying to find a connection between Italy and a tortoise. In the history of Siena I found that the tortoise is the crest of one of the seventeen wards of Siena."

"Wards? What wards?"

"Siena is divided into seventeen districts or wards: each ward has its name, its chapel and its flag. Most of the wards are named after animals or birds. There's the she-wolf, the owl, the goose, and the tortoise..."

"Well, I'll be hanged!" Don said. "Isn't this something to do with the festival of the Patio: the annual horse race?"

"Yes, that's right. There has always been rivalry between the wards, dating back to the tenth century. They keep up their rivalry by racing a horse blessed by their church, against the other horses representing the other wards."

"My stars!" Don said, starting to his feet. "This could be the clue we're looking for. It would explain why the knife is a copy of a medieval weapon. This killer could be a crackpot who has borrowed from medieval history. I must tell d.i.c.ks. He'll know if the Italian police have worked this line or not. Find out if he can see me right away, will you?"

Marian called up d.i.c.ks' office.

"He'll be waiting for you," she said when she had hung up.

"Then I'll get off. Marian, go and buy yourself a hat: money's no object and charge it to my account. You are an exceedingly bright and clever young woman."

"Thank you, but that's what I'm paid for," Marian said, smiling.

"I'll take you out to dinner tonight," Don said as he made for the door. "If you're not wearing that new hat, there'll be trouble."

Twenty minutes later he walked into d.i.c.ks' office.

"Any news of Gina Pasero?" he asked as he closed the door.

"Not yet," d.i.c.ks said. He looked tired and worried. "Have you something for me?"

Don straddled the office chair, resting his arms along its back.

"Are you still keen for me to go to Italy and see what I can dig up?" he asked.

d.i.c.ks lifted his eyebrows.

"I thought we had gone into that, Mr Micklem. You said..."

"I know what I said," Don interrupted. "That doesn't answer my question."

"Yes, I'm still keen," d.i.c.ks said. "I think you could easily find something that would put us on to the Tortoise."

"Good. I've decided to go," Don said. "But on one condition: I want a clear field for at least a week."

d.i.c.ks took out his pipe and began to fill it.

"I don't follow you," he said. "What do you mean - a clear field?"

"I'm backing a hunch. I don't want you to contact the Italian police until I have explored a little. Too many fish in the pond will stir up the mud."

d.i.c.ks looked doubtful. . "This is a murder case. If you have any information..."

"I said a hunch, not information. I'm not keeping it a secret. My secretary has been doing some research on the tortoise,"

Don said, "and she's turned up something that may give us the lead we're looking for. Ever been to Siena, Super?"

d.i.c.ks shook his head.

"Siena is a medieval town. They take a great pride in keeping it that way. Twice a year the festival of the Patio is held in the main piazza. It consists of a procession of men in fifteenth-century costumes and a horse race. Each horse represents a ward. For hundreds of years Siena has been divided into seventeen wards or districts. Each ward is a self-contained unit with its own crest, leader, church, traditions, and flag. The wards are named after animals, birds and reptiles. One of these wards is named after the tortoise."

d.i.c.ks' deep-set eyes showed his interest.

"I know it is a long shot: no more than a hunch," Don went on, "but it might easily be the lead we are looking for. We are hunting for a killer who uses a copy of a medieval knife, who calls himself the Tortoise and who is apparently in rivalry with other Italians. The facts can be made to hook up with Siena."

d.i.c.ks shook his head doubtfully.

"It is a long shot: overlong I think."

"That's why I'm justified in asking for a clear field," Don said. "It isn't more than a hunch, but it needs careful handling. If the Italian police started asking questions about the Tortoise in Siena, and if the Tortoise happens to be there, he'll vanish before they can get their hands on him. I could get information, if there is any information to get, without stirring up too much mud. Do you see what I'm driving at?"

d.i.c.ks rubbed his jaw.

"All right," he said. "I'm only agreeing because I don't think my opposite number in Italy would bother to investigate this line, Mr Micklem. He hasn't much imagination. If I haven't heard from you after a week, then I'll send him a report. How's that?"

"Fine." Don got to his feet. "I'll be leaving in three or four days. If I dig up anything, I'll let you know."