It had awoken. The siren call of its power stretched through the emptiness of space to one that had been waiting for aeons. He felt it stir in his mind, power flooding through his body.

It was time. It was in the hands of one that was weak. A fragile vessel that would be easily shattered.

He had to find it. The future of his race depended on it – and the descendents of he that had snatched it from him – the destroyer of his race – would pay for their arrogance and presumption...

ooo0ooo

At exactly ten minutes to eleven the following day, Professor McGonagall left her office, and walked slowly down the path to the main gates. To attempt to land the Bifrost within the grounds was too dangerous, given the complex and ancient protections in place around the castle, but even though the summer had faded into a cool and colourful Autumn it would be no hardship to walk to the edge of the wards, to greet her guests. At exactly eleven o clock, a streak of multi coloured light shot out of the sky, and two figures stepped from the point at which it made landfall. The Professor's hand went involuntarily to her lips. So familiar, both of them, teachers at Hogwarts until two years ago. She had seen Hermione blossom from a plain and bookish schoolgirl, to the poised elegant woman before her; and the man beside her, her hand in his, that she had plucked from the gates of ruin and death, and restored to life, love and his proper place, was now her match in every way.

"Professor McGonagall!" Hermione stepped forward, wrapped against the morning chill in a cloak of dark red velvet, the hood drawn over her head. She embraced her old Professor and friend warmly.

"Princess Hermione, Prince Loki, welcome back to Hogwarts, it has been too long".

Loki kissed her warmly on the cheek. "Professor McGonagall, let us have none of that, as you love us. Now we are no longer Professors, Loki and Hermione will suffice" Turning away from the gates, he offered the elderly witch his arm as they walked back to the castle side by side.

They talked of trivialities, as they walked; of changes that had taken place at the school since their departure, and of recent events in Asgard, including the birth of Bjarte and Brandt, for it would not do to speak of anything of a sensitive nature outside the security of the Head's Office.

When they eventually ascended the enchanted spiral staircase, they found none other than the Minister of Magic, Kingsley Shacklebolt himself, seated in one of the armchairs by the fire. Hermione, who knew the Minister of old, from the days when he had been a member of the Order of the Phoenix, nearly fifteen years ago, smiled in delight, stepping forward to great him. Seeing her now, for the first time in nearly ten years, Kingsley's eyes widened in astonishment.

"Hermione Granger! Merlin. I would never have recognised you!" Catching Loki's cool appraising stare, he recollected himself. He bowed his head respectfully. "My apologies, Princess Hermione. And may I congratulate you – two year's too late – on your marriage."

Hermione smiled up at her old friend. "Kingsley, it is always a pleasure. May I present my husband, Loki, Prince and Lord Chancellor of Asgard." The two men shook hands, eyeing one another a little warily, although Kingsley was wise enough to bow his head deferentially, in acknowledgement of Loki's rank. He knew of this tricky, brilliant Prince of course, of his troubled past, and the miraculous change wrought in him by the woman that was now his wife. It would be wise to treat him with the appropriate formality for the time being.

When they were all seated around the fire, and Miggs and the Headmistress had served refreshments, all eyes turned to the Minister.

Kingsley cleared his throat, a little nervously. "First of all, I would like to thank you both for coming so quickly, and Professor McGonagall for arranging this first meeting." Loki's eyebrows raised at the inference that there would be a second meeting. Seeing this, Kingsley elaborated further. "I am hoping that you may be able to meet me in London tomorrow. But let me start from the beginning."

He took a deep breath. "There has been a break in at Gringotts".

Hermione frowned. "That's terrible Kingsley, but surely this is a matter for the Aurors?"

"Normally, yes, although this is only the third break-in at Gringotts in the memory of even the oldest goblin. The first was when Professor Quirrell broke in and attempted to steal the Philosopher's Stone, immediately before you started at Hogwarts. And the second..." He raised his eyebrow at Hermione who had the grace to blush.

Loki looked at her, confused. "Hermione?"

"Er, that was Harry, Ron and me, immediately before the Battle of Hogwarts. No charges were pressed, because we did it to destroy a Horcrux, and ultimately Voldemort. We did do quite a lot of damage though. Especially the dragon"

Professor McGonagall coughed – choking on her tea. "A dragon" she gasped weakly...

Now it was all coming back to Loki - he remembered Hermione telling him about this not long after he arrived at the School. Escaping on the back of a dragon wasn't something that you forget in a hurry.

Hermione looked at the Headmistress apologetically. "It wasn't common knowledge at the time. When we have a little longer I promise I'll tell you the whole story. But yes. There was a dragon and we made a terrible mess."

Kingsley shifted a little in his seat. "Well actually, that is part of the problem. How familiar are you with the structure of the bank."

"Not particularly . The goblins are very secretive."

"Right. Well as you probably are aware, the vaults are in the labyrinthine cave system under Diagon Alley, with the older, higher security vaults lower down in the system.

What you are probably not aware of is that far below even the eldest of the modern vaults, is a much smaller system of around a dozen truly ancient vaults, many of them thousands of years old.

The vault that was broken into was one of these very ancient vaults. And that is part of the mystery. Given the age of the vaults, it is impossible to tell who they belonged to. What we can be fairly certain of is that they were not of our race, as we were busy chasing woolly mammoths at the time"

Loki now looked intrigued. "Do we know what was stolen?"

Kingsley shook his head. "Not specifically, but the goblins do have parchment records that the vault in question contained a single casket of an undetermined metalic material, decorated with runic script. They copied the script and the decorations as best they could, but even their best curse breakers and language experts over the centuries have been unable to decipher them. It is this casket that is now missing."

Loki frowned. "And what makes you think that I can help?"

"Because to the best of our knowledge, the runes are probably a variation on a very ancient Norse dialect, not hitherto known to any expert either magical or muggle."

Loki leaned back in his chair smiling, his eyes on Kingsley. "You believe that they may be Asgardian don't you?" Kingsley nodded.

Hermione's mind however, was elsewhere. "I still don't understand HOW they got in though. I've been in those vaults, there are traps, spells everywhere. Simply getting past the goblin on the desk is virtually impossible."

"Well, I'm afraid that is where you, Ron and Harry come in. When you flew out of the Gringott's vault on the dragon, you caused a considerable amount of structural damage. It appears that some of this damage may have caused the actual bedrock beneath the vault to shift, causing a number of small structural faults to open in the lowest level of the vaults. Britain's top magical trackers have detected magical residue around one of these faults, and believe that a small group of wizards may have accessed the fault via the muggle underground. The actual location and content of these vaults was known to only a very few key goblins, one of whom apparently went missing three weeks ago."

Hermione was looking positively horrified to discover that it was her actions that had contributed to the crime. Loki was gazing into the middle distance, lost in thought. "Why tomorrow? We really need to go this afternoon. Now."

Kingsley looked apologetic. "The problem is that we are dealing with the Gringott's goblins. They are – not easy – at the best of times."

"And then there's me" Hermione stated flatly.

Kingsley nodded reluctantly. "Goblins have long memories, and a number of them were injured and even killed when you broke out. They accept that you did what you did for the best of reasons, and that is the only reason that they are prepared to allow your involvement in this case. That does not mean that they are prepared to be overly cooperative however, and they have specified that tomorrow morning is the only possible time that they can allow you to view the records and visit the vault."

Loki's eyes widened, suddenly. "We have to visit the vault. The lowest deepest level in a labyrinth of caves." He looked at Hermione, his face suddenly very pale.

The Headmistress – understanding – looked concerned. Kingsley looked merely looked puzzled. "Is that a problem. The goblins will guide us."

"I'm not very good in enclosed spaces – particularly caves. I had a – ah- bad experience in one a few years ago."

Hermione took his hand. "Would a mild calming draught help. I'm sure that I could borrow a lab this evening."

Loki squeezed her hand appreciatively. "That's kind of you alskling, but I suspect I will need the full range of my powers tomorrow and any kind of potion takes the edge off them. I will be alright." Rising he turned back to Kingsley. "Minister, thank you for contacting us, my wife and I will be happy to meet you in London tomorrow. Where would you like us to meet?"

Taking the hint that the meeting was at an end, Kingsley rose to shake his hand. "I would suggest that we meet in my office first. Would 10.30 be satisfactory?"

Hermione rose to say goodbye. "That will be fine Kingsley, thank you. If we are going to the lowest reaches of the Gringott's vaults, may I suggest that we all dress appropriately. I cannot imagine that it will be very pleasant down there."

"An excellent idea. Will you be staying overnight at Hogwarts, or would you like me to book you into the Leaky Cauldron?"

"Thank you Kingsley, but I believe that we will stay overnight here, if that is alright with Professor McGonagall?"

The Professor smiled "You and Loki are always welcome at Hogwarts Hermione you know that. In fact your old room has been kept for you, in case of just such an eventuality"

Hermione looked up at her old friend. "Are you apparating back Kingsley" when he nodded his affirmation, she turned back to Loki. "I'm just going to walk Kingsley back to the gates, I won't be long. We have things to catch up on.."

ooo0ooo

At this time of the morning Stark Tower was silent. Bruce was fairly certain that Steve Rogers was probably out for a run, or pounding a punch bag in the gym. They would be lucky if Tony showed up before lunchtime – as a rule, seeing him up at this time – just a little after eight – meant that he had been working all night and may or may not be off to bed, depending on whether or not Jarvis had time-locked him out of his lab. Banner sipped his first coffee of the morning, and idly flicked through his emails.

Eric Selvig...

Now there was a name he hadn't heard for a while. Jane Foster's mentor had retreated to London after the Battle of New York. Occasionally publications with his names attached would find their way onto Bruce's computer, but this was probably the first direct communication that Bruce had ever had from him.

Banner was suddenly aware of another presence behind him. A warm female presence, leaning familiarly over his shoulder, soft red hair brushing his cheek.

Within him, he felt The Other Guy humming happily. She usually had this effect on him. On both of them if the truth be told.

"Good morning Natasha"

She took a sip of his coffee. The gesture of casual intimacy was both delightful and frustrating... "Anything interesting?"

Bruce nodded, trying to marshal his fractured thoughts – not unusual when Natasha Romanoff was so close that he could smell the subtle sweetness of her shampoo, and the faint scent of warm damp skin which indicated that she had only just had her post workout shower. Aware that she was looking at him – a look of faint puzzlement between her brows, he pulled himself together.

"It's from Eric Selvig. Apparently he's been trying to get a hold of Jane... without success"

Natasha shrugged. "She's a Queen, and a wife, and she's only recently given birth to twins. It's hardly surprising if she doesn't have time to ponder scientific problems. Does he say what it's about?"

Bruce had been reading Eric's message while listening to Natasha with half an ear. "Hmm, this is interesting. Apparently Selvig has detected a number of "significant and escalating gravitational anomalies" that he wants her to look at."

Natasha looked at the data. "Should we be worried?"

Bruce shook his head. "I'm not sure. It's lunchtime in London. I'll give him a call..."