Instantly, the fight was over. The boy doubled up as the breath whooshed from his lungs. For an instant he hung in the air like a question mark, then he dropped to the floor.

Solicitously, Mark hauled him to his feet, lowered him into a chair, massaged the middle of his chest, and then allowed his head, shoulders and arms to flop forward on to the table. As the air wheezed back into the boy's lungs, Mark picked up the gun which April had dropped among the negatives and broke it open.

A moment later he exclaimed in surprise. "Look here — he wasn't bluffing!" he said. "This is not a sideshow pistol! It's loaded in all eight chambers...the shells are .32 calibre, I should think!" He shook the deadly slugs into the palm of his hand and raised his eyes to hers. "You knew, didn't you?" he asked softly.

"Of course I knew," the girl said coolly. "But there's more than one kind of bluff, isn't there? It was the only way I could think of to make him lower his eyes and give you an opportunity to do your stuff! I know how you love to make with the Superman routine."

Slate grinned. "Every man's Mum, that's you," he said lightly. "Good on you, just the same, as the Aussies say." He dropped a hand to her shoulder for a moment and then walked over to the boy.

The rasping sounds of returning breath had changed to a hoarse but more rhythmic noise. Ernie Bosustow was crying.

"Come on then, mate," the agent urged, not unkindly. "It's not the end of the world to be beaten in a little fight. And, after all, I am as you might say a professional! Sit up and let's have a word with you..."

But the boy kept his head buried in his arms, his shoulders continuing to shake.

After a moment, April and Slate exchanged glances and the girl moved over to the sobbing youth. "Ernie," she said quietly, laying an arm along his shoulders, "pull yourself together, man. Maybe we can help you. We're not really on the other side, you know."

He raised a red and puffy face and stared at her. "I'm sorry," he said at last in a low voice. "It wasn't the fight, you know. He beat me fair and square an' all, and I reckon I can take a hiding as well as the next man."

"What is it then? What's the trouble?"

"It's... it's... Oh, every goddam thing," the youth burst out. "Can't do right, can 'ee? Simply can't." He stared at the wooden wall of the caravan, blinking.

"You mean about Sheila, and...and your brother, and everything?" April said sympathetically. "I know. You do seem to have had a rough deal."

"Rough deal be... Never mind. No, it's just everything. Every rotten thing. It's not enough that they have to kill my girl..." He swallowed and then went on: "... It's not enough that they make her fall for some loud-mouthed swaggerin' slob first, and we have words about it. It's not enough that they kill my brother — but they have t' bother their great fat heads suspectin' me of the murders!" His voice, which had been rising with anger, broke suddenly.

Mark Slate, mentally ticketing him as "Younger-son-with-chip-on-shoulder", reflected with an inward smile that he sounded for all the world like the pigeon who was afraid of serpents in "Alice".

"But, Ernie," April was saying reasonably, "you can hardly blame the police, can you? After all, you were heard to threaten Sheila — by several independent witnesses, too."

"Threaten her? I wouldn't have touched a hair on her head! Not me."

"But you were heard to say —"

"We had a quarrel. Sure we had a quarrel. I never said we never. Sure I said words to her — who doesn't have words when they're rowin'?"

"What kind of words?"

"Oh... You know I told her I'd break her ruddy neck if I as much as caught her lookin' at this popinjay again. I said I'd rather see her dead than go out with him..."

"Then, surely...?"

"But that's not threatenin', is it? God, there's a world of difference between a man who says — kind of between his teeth, Like — 'I hate you. I'm going to kill you', and a mum, say, who tells her little girl: 'If you don't shut up that row, so help me, I'll strangle you!'... I mean, she don't strangle the little girl, does she?"

"Well, no. I see what you mean. But —"

"So what's the difference? When I tell Sheila I'll strangle her — or I'll break her neck or whatever — if I catch her lookin' at loud mouth again, I'm speakin' like that mum, aren't I? Figure of speech, that's what it is; just a figure of speech. I don't mean that I'll actually put my hands round her neck and choke the life out of her; I mean I'll be ruddy furious... I mean I might even get cross enough to slosh her one. But that's all."

"There is one difference between you and your mum, though," April said gently. "As you said, that mum doesn't really strangle that little girl. But your little girl was strangled, as it were. Somebody did murder Sheila. And although I understand what you mean, when remarks like that are written down and read by someone who didn't hear the quarrel — well, they tend to appear just as bad, and just as menacing, as words from someone who speaks between his teeth and means it."

"But I tell you I wouldn't have harmed a hair on her head. Oh, forget it. You're just like all the rest," the boy muttered. He stared at her angrily, the bright blue eyes glittering in the characteristic, florid Bosustow face.

"There's one difference between us and what you call the rest," the girl said levelly.

"What's that? As if I cared." He bad relapsed into sulkiness now.

"Just this — that we're not interested so much in pinning the responsibility for the murder on somebody, as in finding out what really happened, in discovering just why she was killed — and who really did it."

Bosustow stared at her again. Slowly, he turned and gazed at Mark. "That's it," he said. "I'd forgotten. Who the hell are you, then? What are you doin' in Harry's caravan? What have you got to do with all this? — You don't sound like ordinary burglars, somehow."

For the second time, April Dancer exchanged meaning glances with Slate. Their eyes met, held, and then Slate imperceptibly nodded. The girl swung round and looked earnestly at the boy. "I'm going to take a chance on you," she said. "I'm going to let you in on something. But first, answer me a question: did your girl ever seem to be... well, a little odd, shall we say? I mean, was she like your other girlfriends? Or was she different in any way?"

"I'd never met anyone like her, if that's what you mean. She was... she was a knock-out. There'll never be anyone like Sheil." He sniffed and swallowed noisily.

"That's not what I mean exactly, Ernie. I meant... oh, things like punctuality, putting off a date, altering arrangements. That sort of thing."

"Oh." He hesitated. "Well... yes, I guess she was a bit exasperatin' at times. How did you know?... I mean, she was forever changing the times we were to meet, and she did put off things, at that. I used to think she was maybe standin' me up, and that made me mad."

"Exactly." April paused impressively. "She wasn't standing you up, Ernie. She had to alter things because she had special work to do; work that was quite apart from her sideshow here at the circus, important work."

"You don't mean..." He stared at her unbelievingly. "You don't mean... secret work?"

The girl nodded. How fortunate, she reflected, that the current fads in television and cinema entertainment had acclimatised people like Ernie to accept without question that to be a secret agent was to have a métier as commonplace — if perhaps slightly more glamorous — as that of postman, doctor or insurance salesman! "I can't tell you any more," she said. "I'm not allowed to. But we are colleagues of hers... And that's why we must find out who killed her and why... We should like it very much if you could help."