Ron and Hermione swung around in relief. They had been advancing purposefully up the valley side, wands out before them.

"It's OK, Harry," Hermione said composedly. "We weren't leaving."

Harry absorbed the scene in front of him. Ron and Hermione had been stalking up the slope, wands raised threateningly. Snape lay flat on his back some distance away looking as furious as Harry had ever seen him. Harry guessed he had been hit, hard, by two violently delivered expelliarmus curses.

"Here." Hermione tossed Snape's wand back over to him, and he scrambled to his feet with a menacing noise in his throat.

Harry blinked. Had he really just seen Hermione, coolly, calmly, take on Snape? A teacher?

It seemed so.

Snape recovered his poise quickly, although he still looked extremely annoyed.

"Very entertaining, Weasley, Granger. You will not make Aurors, you know, if you persist in letting your emotions overrule your judgement. You will hear more of this later, I can assure you. However, now Potter has deigned to rejoin us, the most important thing is to depart. As fast as we may."

Hermione and Ron had lost interest in Snape, however, and were looking at Harry anxiously. "Er – Sirius – ?" Ron tried tentatively.

Harry shook his head. "Couldn't bring him with me," he said flatly. "But I spoke to him, I'll tell you later. For now – we really do have to get out of here."

Snape cast his eyes towards the heavens. "Potter finally shows a glimmering of sense," he muttered under his breath. "We will need a speed spell," he told them. "And, we will - ah - need to hold onto each other."

Snape regarded them with curling lip and an expression of the utmost repugnance. He was clearly considering which one of them he could best cope with actually touching. Finally, with the manner of one picking up a man-eating spider in his bare hands, he grabbed Hermione's arm. Ron took hold of her as well, and Harry hung on to Ron.

The speed spell was dizzying. "Think – of – shore!" they heard Snape telling them repeatedly through the rushing winds and choking mists.

They did. The journey was swift, but not swift enough, and nor was it pleasant. At last (at long last, as Ron said bitterly) they flopped down on the beach gasping for breath, and feeling as if they had just been smothered by barrel-loads of wet fish.

The shore was just as it had been when they arrived. The wet sands shone silver in the metallic light, and the sea roiled darkly. There was no sign of the kelpies.

"You may now drink your potions," instructed Snape, fetching his own from under his robes.

They each drew out their bottles and all four swallowed what remained of the Essence of Mag Mell. Harry was subconsciously filling his lungs with air prior to his immersion.

This time, though, they were not plunged into the waters. Instead, the air some metres in front of them began to swirl. Round and round it went, faster and faster, until a churning vortex hung before them. Harry looked at it sideways, and could have sworn strange beings were darting about within it like silvery eels.

"We had better keep in contact with each other again when we go through," Snape said reluctantly.

They rose and approached the vortex. Before they were within six metres of it, the tall, cloaked figure they had seen before shimmered into existence in front of them. It raised its head to confront them with the shrouded depths beneath its hood, and it spread its arms to bar their passage.

"You may pass," it said to Snape, "but these three may not."

The being's voice flowed towards them, cold and dispassionate as liquid ice.

"What do you mean?" Snape demanded, his eyes hard.

"They may not pass."

She, or he, or it, said nothing more. Its silence had the implacability of a glacier.

Snape turned to Harry, Hermione and Ron. "Did you," he demanded softly, "did you by chance eat or drink anything from this place?"

They shook their heads. "No really, Professor Snape," Hermione assured him earnestly. "We didn't, not even when we were really thirsty. We didn't even use wands to conjure drinking water in case it would turn out actually have come from here."

Snape seemed marginally soothed by their response. "Did you then – did you take anything from this realm that was neither freely given nor paid for?"

Again, they shook their heads. Hermione, however, let out a sudden gasp; she clapped a hand to her mouth. Ron and Harry looked at her in puzzlement.

Snape put a hand to his brow and closed his eyes. His fingers trembled slightly.

"Even for you," he said to them in a low, even, tone, "whatever you have done, it was an act of quite staggering stupidity! Do you not understand? This realm abides by the old laws. It is a place of blood magic, of sacrificial magic. Have you never read any of the ancient tales? Did it never enter your heads to wonder why this place is considered so dangerous?"

Hermione (of course) remembered very well what Snape was referring to: ". . . what you take but do not pay for, you will forfeit in the sacrifice of your living flesh". She did not like the sound of this: at all.

Snape turned to the being.

"State the nature of the debt. If," he added rather bitterly, "by so doing, you do not decide we have incurred yet another debt."

"It is permitted to tell you of these things." The voice remained devoid of anything resembling emotion. It was pitiless as the stars. "There is one matter before us."

"What?" Snape folded his arms and glowered.

"It is a matter of advice given. Upon your entry into this place," it addressed Harry, Hermione and Ron, "you asked me how to find the one you sought. I told you."

"But," Harry stammered in indignation," I didn't realize! I didn't know! You never said!"

"You had been told the rules of this place, mortal one. And those rules were in fact, given to you freely: there was no onus on me to tell you of them. And now.. I choose to make my claim. It is long since we have had mortal flesh for the ancient Sacrifice."

"Why," Snape was hissing at them under his breath, "can you never do as you are told!"

The being raised its silvery arms towards the skies. A weighing scale appeared before them. One side of the balance pans was heavily weighted down with a dark, pulsating mass. Curiously, this dark mass seemed to be composed of emptiness itself. It put Hermione in mind of the essence of the void.

"See," it whispered fluidly. "This is what you owe to us."

It folded its arms and gazed into the distance.

"And what," Snape demanded, "would you estimate this debt to be worth in weight of human flesh?"

It assessed the scales. "A leg from one of these children here should suffice. You may choose amongst yourselves as to which. It matters not to us." The gleaming figure might as well have demanded a handkerchief, or a spare pencil, for all the feeling in its words. "Or, if you prefer, you may offer your arm instead. It is not your debt, but we would accept it from you in lieu."

From the look on Snape's face, Harry guessed this option was not high on his list of priorities.

"Well," Ron said to Harry in a sickly voice, "Madam Pomfrey is really good, isn't she? Not much she can't heal! And, and there's always St. Mungo's!"

Harry had a suspicion that regrowing entire limbs lost in this fashion might be beyond even magical healing abilities. Otherwise, so many of the Aurors would not still bear such deep scars of conflict. His thoughts flicked to Mad-Eye.

"Take my leg!" he blurted out, before he could spend too much time considering the consequences of what he was saying. Snape was regarding him strangely again. "It's all my fault; no-one would even be here if it weren't for me! So take it from me." Almost, in the corner of his eyes, he could see three snake-haired women with bleeding eyes.

"As you wish." The figure shrugged, indifferent. It stretched out a hand. A long silver blade began to coalesce from the silver mists. "Lie down. It will be easier to attain a clean stroke."

At least it looks sharp, Harry thought miserably, bracing himself. And he'd still be alive, it could have been worse. Harry's knees were trembling so much that he sank to the sands almost with relief. His heart was thudding against the walls of his chest.

It all happened very quickly. Harry did not have time to dread what was about to come. Snape had only just begun to extend his hand as if in protest, and Ron and Hermione to exclaim in horror. Then, abruptly, it was already over. They stood frozen. Harry thrashed and jerked on the sands, blood gushing from his upper thigh, uttering thin and incoherent screams. Hermione was pressing her fist hard against her mouth, and Ron was absolutely white beneath his freckles.

The ball of emptiness drifted out from the scales. These now hovered in perfect balance. Snape sank swiftly to his knees besides Harry and started muttering charms to stem the spouts of blood. Like Ron and Hermione, he looked quite ill.

"I have this correctly, don't I," Hermione spoke up shrilly. Everyone turned to look at her in surprise. "Everything has its price, right? For whatever is taken, payment must be made?"

"That is correct," the figure said, almost absently. It looked at Harry, and stretched out a hand to pick up his leg.

Hermione was speaking again.

"Then," she proclaimed with an odd note of triumph in her voice, "you may take your pounds of flesh, but with it, not one drop of blood!"

Everybody froze. The figure paused in the very act of gathering up Harry's leg.

"In fact," Hermione continued; her voice was quavering, but she drove on with determination, "you are in our debt now. You have wronged us. You have taken from us something you are not entitled to. Harry's leg, that is: not only flesh, but also blood and bone. We want payment."

The being lowered its sword. "And what payment would you seek for this supposed error?"

Hermione smiled grimly. "Heal him. Return his leg."

The being made no reply. Merely it knelt by Harry's side, and rejoined his leg to his body. To Harry it was as if he could feel flesh and bone and sinew putting out new tendrils and twining together. It was a peculiar sensation, but it did not hurt. The pain vanished as swiftly as it had been inflicted. He lay flat, shock rendering him immobile.

"Pass, then," the being breathed. "Debts have been paid. You may pass."

The figure dissolved.

Harry managed to sit up, and found Hermione had flung herself down beside him to hug him fiercely. He grinned shakily at her.

"All better, Potter?" Snape inquired. His hands were entwined in his robes as if to hide the fact that they were still trembling.

Harry nodded, and proved the truth of it by getting to his feet. He still felt very wobbly indeed, but his leg seemed just as it always had done.

"Hermione," breathed Ron. "How brilliant are you! How did you think of that?"

"Shakespeare. It's how Portia gets Antonio off in A Merchant of Venice." Hermione smiled modestly. "It's a very well-known story."

"Whew."

Ron shook his head in awe. Even Snape was looking at Hermione with something approximating to approval.

"And now, let us finally depart before the Gate closes."

Holding on to one another, one by one they stepped through the vortex.