Standing at the top of a cold, dark stone stairway, illuminated only by the tip of his wand, Erebus and Zornitsa paused.

"You don't owe me anything and I don't owe you anything," Zornitsa whispered. "Everyone's going to be partnering up. I'm not partnering with anyone who's not on their way up."

"Fine by me," Erebus whispered. "Let's just get on with this."

The pair of them tiptoed down the stairs. The castle creaked. The light from Erebus's wand started to dim. They came upon a large oak door. Erebus peered through the keyhole.

"I can't see anything on the other side," he said.

"Alohomora!" said Zornitsa, waving her wand at the door. Nothing happened. She pulled at the handle but it wasn't moving.

"I think I can remember some other opening charms," said Erebus.

"No need," said Zornitsa. She slammed her tiny fist into the lock. The oak wood cracked around it. She hit it again and the whole lock tore through the door and dropped out on the other side.

"Wow." Erebus was stunned by the display.

"I took a strength potion earlier just in case," said Zornitsa. Erebus couldn't think of any potion that would also protect her knuckles, but he decided not to press her on it.

He pushed the door open and the pair of them walked into the basement. Inside was a long dark brick-lined room with a low ceiling. Banded along the walls and ceiling and across the floor, were strips of lead. In the centre of the room was a huge cage with thick bars and wire mesh. Branching off of the main cage was a warren of smaller cages. These cages could be separated, closed off or taken away. Inside the cage huddled the mass of erklings. Most were sleeping, huddled under rags. Some were drinking from water bottles or eating from bowls of scraps.

As Erebus and Zornitsa walked closer they saw pockmarks and scorches in the floor and ceiling. Stacked along the walls were various crates stacked with old vegetables. Everywhere there was broken furniture and in one corner leaned a mildewed painting of a ruined castle. The erklings started clamouring and waking each other up when they saw their would-be rescuers approach.

Erebus tried an opening charm on the cage but it had no effect. Zornitsa leaned down to bend the bars but the erklings tried to bite her fingers.

"Ow! Quit it!" she said, nursing her hand.

"You're not getting our blood!" said one of the erklings. "We'll get yours!"

"I don't want your blood you ungrateful little creeps," she said, kicking the cage. "We're trying to get you out of here."

"I've got an idea," said Erebus. He pointed his wand towards the cage, took a deep breath, and chanted, "Plumbaeiris!"

The room was filled with an intense copper glow. Erebus could barely make out the end of his own hand. The glow lasted for a long moment, so long he began to wonder if the effect were permanent. But then it faded and everything was as it was. Except that all the lead in the room had changed to copper including the cages and the banding on the walls and ceiling.

"That was amazing!" exclaimed Zornitsa, before turning to the confused erklings. "Okay you all can disapparate now. The lead has gone!"

Tentatively, the erklings began to concentrate and one-by-one they popped out of the cage. They didn't get far as their powers were blocked by the walls themselves.

"There must be lead even deeper in the stone," said Erebus.

Pretty soon the pair of them were surrounded by all the erklings. They were beginning to stretch out and look around. Erebus spotted the erkling with the brown eyes who he had tongue-tied the other day.

"You!" she said. She was wearing the same rough dress as before and he noticed for the first time how long and sharp her claws were.

"I'm sorry about before. This makes up for it, right? You're all free to go," he pointed to the door.

"Another wizard trick," she spat.

"You speak too much, Lizenz," said a tiny erkling with a missing claw on his left hand. "I'll have my revenge now!"

He leaped at Zornitsa, razor claws outstretched. She backhanded him with great speed and the little erkling landed in one of the piles of vegetables. Erebus gripped his wand and searched his mind for the right spell.

Lizenz took a deep breath in through her nose and then held up her hand to the others who were eyeing up Erebus and Zornitsa hungrily.

"Wait!" she cried. "My nose didn't deceive me. These are truly half-breeds. Perhaps they really do mean to free us."

"Of course they do!" bellowed a voice from the mildewed painting. An out-of-breath ancient goblin was jogging across the parapet into view. It was, of course, Urg. "Run to the door and disapparate, you fools! You'll be fine when you're clear of the room."

The erklings didn't need to be told twice and swarmed as a pack towards the door. Once they passed the threshold they all popped out of being. Lizenz was the last to go. She turned back at them and said, "If you ever cast a spell on me again I'll bite out your tongue, and then the rest of you!" With that the closest thing to a thanks Erebus expected, she too disapparated.

Panting and exhausted, Urg leaned against the inside of the frame and composed himself. Zornitsa looked curiously at Erebus as if seeing him for the first time, while Erebus returned the look.

"That erkling didn't know what she was smelling," said Zornitsa.

"She was just finding an excuse to save us both," said Erebus.

"Exactly." Zornitsa said.

"Come on, who do you think you're both kidding" said Urg at last. "Trust a wizard to be ashamed of their inhuman heritage!"

"I don't know what your talking about," Zornitsa said, turning away.

Erebus felt the shame inside him, as Urg had said. But he also felt the burning need to connect with someone about it. "The… the erkling was right. I mean, I don't know about you, but I do have… inhuman blood."

As he said the words, he was overcome with regret. What if she told everyone? They didn't even allow muggle-borns into Durmstrang, how would they possibly accept someone with his heritage?

Zornitsa looked down at the ground. "I know," she said. "She was right about me, so I knew she'd be right about you."

"No one can know!" they both said at once.

"Shake on it," said Erebus, putting out his hand.

"It has to be a blood pact," she said, taking out her wand.

"I don't know how..." said Erebus.

"Follow me," said Zornitsa. She took her wand and dug it into the flesh of her palm. "Make the cut."

Erebus did the same. He focused his mind on he tip of his wand as he pressed the pine into his palm. He tried not to cry out in pain as he drew blood.

"Now, hold it to mine," she said. "I swear that I will not betray your secrets!"

"I swear I will not betray your secrets!" Erebus vowed as he pressed his wet palm against Zornitsa's.

Her hand was much smaller than his but he could feel her power and focus was strong. Two drops of blood floated up from them and span around in a tiny orbit before merging together. A perfect vial formed and floated slowly to them. Erebus moved his hand away and felt his palm was healed. Zornitsa took the vial out of the air.

"It is done," said Zornitsa. "We can speak with each other."

It was then that she remembered the third person in the room. She held out her wand and turned to the painting, but Erebus grabbed her arm before she could do anything.

"Urg isn't going to say anything," he said. "I'm the only ally he has here, isn't that right?"

The proud goblin looked out of the painting, and, with bitter dejection, said, "Aye. You did the only noble thing I've seen this century. And by the sound of it, you both have more in common with me than I'd realised. I'm a half-breed too... I'm half canvas!"

His lame joke cut the tension in the air and Zornitsa lowered her wand. "So…" she said, "what are you?"

The answer was on Erebus's lips when he noticed a grey mist form about the room. It coalesced into the haggard form of the duelling mistress, Professor Kjerring.

"Well, well, well, children," she croaked before licking her lips. "I thought I was going to have erkling for supper, but instead I find you two here..."