Gobbo the house-elf staggered through Crimmin Alley with a (relative to him) enormous bag of groceries slung over his back. It was a dismally murky night in Upper Flagley: only a sliver of moon, and a handful of the brightest stars, could be seen through the thick blanket of clouds that had blown up out of the North Sea that afternoon. But Gobbo didn't mind: his mistress had told him to go out and stock up for the ice storm that was coming the next day, and a good house-elf never quarrelled with his mistress. (Besides, Gobbo had marvellous night vision, thanks to his enormous eyes.)

He had made it to the centre of the town square, where the ancient statue of Bellerophon the Bellicose stood in solitary magnificence, when he heard a rustle from one of the nearby bushes; the next moment, a figure in a black, vesica-piscis-shaped cape stepped out into the street, blocking his path. "Spare a minute, Gobbo?" he said.

Gobbo frowned. "Who is you?" he said.

"The name's Spiderman," said the figure. "I want to ask you a few questions about your old mistress."

Gobbo's eyes widened: he knew of only one person who would be sending mysterious people in capes to ask him questions about his old mistress. "You is Dumbledore's man!" he hissed. "You is working with Albus Dumbledore to destroy my mistress's master!"

"Well, not just with Dumbledore," said the figure, with the air of one being fair. "I think there's about a dozen and a half of us, all told. But, yeah, that's the basic idea."

"Then you will get no help from Gobbo, sir," said the elf, with as near an approach to an air of heroic defiance as he could manage while carrying a bag of groceries nearly twice his size. "Gobbo is a loyal house-elf; he does not betray those who were once his masters, even if all the professors at Hogwarts asks him to."

"Well, I don't know that I'd exactly call it asking, what I'm doing," said Spiderman. "It's more a 'tell me what you know or else' sort of situation."

"You cannot frighten Gobbo, sir," said Gobbo superbly.

"Oh, no?" said the figure.

"No," said Gobbo. "Gobbo's only joy in life is to please those whom he serves. He would rather have his throat cut across, his tongue torn out by the roots, and his body buried in the rough sands of the sea, than reveal the secrets with which they has entrusted him. His life itself is worth nothing to him, if it brings grief to their noble hearts."

Spiderman seemed to stare at him thoughtfully for a moment (though, since his eyes were concealed by a black rubber cowl, Gobbo could not be certain of this); then, with a sudden lightning movement, he lunged at the house-elf and grabbed him by the neck, causing the bag of groceries to fall from his grasp and spill out over the lane. As Gobbo struggled fiercely but uselessly against his grip, he turned toward the statue, removed a spider-shaped object from his belt, and shot a grapple into the air, which hooked itself neatly onto the hilt of Bellerophon's outstretched wand arm.

The next moment, Gobbo's head began to swim as he felt himself ascending into the air with great speed. The sensation only lasted a few seconds, but what replaced it was perhaps worse – for, when his head cleared, he found himself twenty feet above the ground, with nothing but one black-gloved hand preventing his tiny body from being dashed against the cobblestones of Upper Flagley's Main Street.

"Nothing, Gobbo?" said Spiderman. "Are you sure about that?"

Gobbo glanced down and attempted to speak, but all that came out of his mouth were some feeble squealing noises.

"Didn't think so," said Spiderman. "Now, then, let's establish some terms. I won't ask you any questions that your masters – past or present – have ordered you not to answer. I also won't let go of your neck until we get back on the ground. In return, I expect you to give me straightforward, honest answers to all the questions I do ask. Is it a deal?"

Hating himself with a fervour that a human can barely imagine, Gobbo nodded.

"Good," said Spiderman. "So: you're currently working for a pair of rich-and-stinking pureblood types called Eobard, isn't that right?"

"Master and Mistress Eobard is the kind of wizards that has made England great," Gobbo croaked. "They is as wise as Väinämöinen, as powerful as..."

"Right, right," said Spiderman. "But you didn't always work for the Eobards, did you? You were given to them by your old masters in 1982, since Rodolphus and Bellatrix Lestrange didn't figure they would have much use for a house-elf in Azkaban."

Swallowing, Gobbo nodded.

"Okay, now I want you to listen carefully," said Spiderman. "Before the Lestranges got sent to Azkaban, Bellatrix got a present from that master of hers: a little gold cup, about yea wide, with two handles and a picture of a badger on the side. Do you remember it?"

"The Hufflepuff cup," Gobbo whispered. "Mistress was so proud... 'See, Gobbo,' she said, 'the Dark Lord trusts me with his greatest treasures'..."

"Charming," said Spiderman dryly. "So she never ordered you not to talk about it, then?"

Gobbo stared at him, a sudden note of alarm beginning to arise in his golf-ball-sized eyes. "No," he said. "Mistress never ordered Gobbo not to speak of the cup... but, all the same, she would not have wanted..."

"Never mind what she would have wanted," said Spiderman. "You can talk about it without going against her orders?"

Gobbo nodded fearfully.

"Then just tell me one thing," said Spiderman. "Where is that cup now?"

A thin, high-pitched whine emerged from Gobbo's throat. "Please, Mr Spiderman, sir," he whimpered. "Gobbo cannot..."

The grip around his neck loosened a fraction of a joule.

"Gringotts!" Gobbo shrieked. "Mistress Bellatrix's vault at Gringotts! She thought it would be safe there... she thought no-one would find it... she never thought poor, miserable Gobbo would..." He broke down, sobbing.

His captor considered a moment; then, abruptly, he flicked his left wrist, and the grapple began to unspool itself and to lower the two of them back down like a fishing line. When they reached the ground, Spiderman let go of Gobbo, who tumbled limply to the ground as though he were a house-elf-shaped rag doll.

"Well, thank you, Gobbo," he said. "You've been a great help. And now I think you'd better get these vegetables picked up and get back to the Eobard place before your masters start wondering where you've gotten to, don't you?"

Gobbo nodded dumbly, rose to his feet, and began putting the scattered groceries back in the bag. When he was finished, he hoisted the bag back onto his shoulders, cast one last fearful glance at the black-clad figure standing behind him, and scurried toward Eobard Manor as fast as his tiny legs would carry him.

"Bad Gobbo," he whispered miserably. "Bad, bad Gobbo..."

A long, red shape snaked out from behind the statue and extended itself towards the spider-cowled figure. "Nice work, little bro," said Fred. "I didn't know you had it in you."

Ron nodded judiciously. "Yeah, I could get used to this," he said.

"Shame about that poor house-elf, though," said Ginny, her long skirt (in which the twins, to complete the mediæval feel of her costume, had rather impractically clothed her) billowing about her ankles as she jumped down from her perch in a neighbouring tree. "It's a good thing Hermione wasn't here, or she'd have you in an Amazon death-grip right now."

Ron shrugged. "I won't say I wouldn't have preferred to dangle Bellatrix herself over a street corner," he said. "One with a lot of cars on it, preferably. But you can't have everything."

"What I'm wondering about," said George, his head emerging from behind the statue on the other side, "is what that elf's going to tell the Eobards."

"Everything, probably," said Ron. "But that shouldn't be a problem. It's not as though the Eobards have any love lost for You-Know-Who; after all, the reason they didn't have a house-elf when the Lestranges gave them Gobbo was that their first house had been crushed by You-Know-Who's giants while they were on holiday."

George looked dubious. "Still, if they were close enough to the Lestranges to get gifts from them, they probably know most of the rest of the potential Death Eaters in England, too," he said. "And you know what kind of a gossip network the old pure-blood families have."

"Well, then, we'd better get a move on," said Ginny. "The last thing we need is for You-Know-Who to have already doubled the curses on the Lestrange vault before we even get to London."

"Can't argue with that," Fred commented.

Ron tried and failed to suppress a grin. Five minutes ago he had interrogating a house-elf from twenty feet off the ground; now he and his siblings were getting ready to invade the second most secure building in Britain. This was living.

"So," he said. "To Gringotts?"

"To Gringotts!" Ginny and the twins chorused.