"We have a bit of a situation."

Mycroft's voice was utterly unsurprised in John's ear.

"Yes, I was informed of some rather . . . unusual occurrences in your area. Would you care to explain?"

"Sherlock's been turned into a ferret."

There was a long pause.

". . . I beg your pardon?"

John sighed, watching the sleek black animal dart around and under and into the couch. The god had disappeared without a trace and John had sent a rather panicky Mrs. Hudson for a lie down and an herbal soother, leaving him to keep track of a Sherlock who was suddenly even more slippery than usual.

"Your brother, Sherlock Holmes, has been transformed into a ferret. By an angry Norse god. Either that or he's slipped something into my drink. If he has, I'm going to kill him. I might just kill him anyway," he added, reaching forward to pull his shoes out of the creature's reach. It hissed at him.

"Ah," said Mycroft, as if that cleared everything up. "Would the god in question happen to be dark haired, somewhat sickly, and more than somewhat emotionally unstable?"

"That's him. Sherlock called him Loki."

"Yes, I expect he did. There is a car outside your flat. Bring the ferret."

The line went dead.

As it turned out, getting ferret-Sherlock to go someplace it didn't want to go was nearly as difficult as getting human-Sherlock to do the same. Mycroft's people were no help whatsoever, though, to their credit, their expressions did not so much as twitch as John struggled to keep hold of the squirming animal. Once inside it retreated to the far end of the seat and glared at him with an eerily familiar expression of resentment. He was nearly certain that no normal ferret had ice-blue eyes.

"This is so ridiculous," he muttered to himself.

The skirmish was repeated when it came time to exit the car, but John eventually managed to wrap the ferret in his jacket. It protested vehemently at this indignity.

"Oh, shut up," he told it. "This is your own fault, you know."

"As difficult as ever, I see."

John did not jump at Mycroft's voice, which echoed dramatically in the empty building. He also refused to be even remotely impressed when the elder Holmes brother stepped out from behind one of the numerous bookcases, his umbrella swinging at his side.

"A library?" John questioned instead. "You couldn't have picked a place where he's more likely to get lost if he runs off? Because I was really looking forward to spending my entire evening chasing after a stroppy rodent."

Mycroft smiled thinly.

"Ferrets are not rodents," he said. He reached towards the not-rodent, only to pull back with a yelp. It was the most undignified sound John had ever heard from him, and the cause was made clear by his bloodied finger.

"He bites," John said unnecessarily while Mycroft wrapped what was undoubtedly a very expensive handkerchief around the wound.

Mycroft gave him a sour look, but did not dignify the statement with a verbal response.

"You have some way to put him back to normal, right?" John asked. "Some secret government shape-shifting machine or something?"

"There are certain . . . options I may pursue."

"Tut, tut."

This time John did jump, spinning towards the voice and automatically tightening his grip on the bundle in his arms. Loki prowled towards them from the shadows, his eyes and his armor glinting.

"Such lies, Mr. Holmes. You may as well tell him the truth now. What good does it do to delay the inevitable?"

The god came to a halt between them, his lips curling into a malicious smirk.

"Your defenses are in tatters, your institutions disbanded and your champion dead. You have neither the technology to reverse the transformation nor the ability to contact those who can. You have no power I fear and no gift I desire. You have nothing, Mycroft Holmes."

Mycroft met Loki's icy smile with one of his own, and John could have sworn that the physical temperature of the room dropped by several degrees.

"You seem very certain of your information, Loki Laufeyson."

Something about that sentence was apparently a terrible insult, because Loki stiffened, the smile sliding off his face.

"Your bluster will achieve nothing, little man. Your brother is lost to you."

And just like that, he was gone.

"Well, that was pleasant," John commented to the empty air, firmly ignoring the chill in his bones. "He's wrong, of course." He turned to face the elder Holmes, who was frowning at the space which Loki had just occupied. "Mycroft? He is wrong, isn't he?"

"Hm? Oh, yes, of course," Mycroft agreed. He gave what was probably supposed to be a reassuring smile, but his face just wasn't designed for it. "I am disinclined to think that Britain is quite so defenseless as certain parties would have us believe. James Moriarty and I are not the only people who prefer to work from the shadows."

"Right," said John, who had no idea what that meant and didn't particularly care. "But you will be able to turn Sherlock back?"

"Undoubtedly," said Mycroft. "With time."

"With time," John repeated. He looked down at the not-rodent in his arms. It had fallen asleep. "I suppose I'll need some food for you, then."