"Sir-" Jarvis addresses Tony inside his Iron Man helmet as Tony swoops through the air.

"Let me guess, the whole royal family's moved in." Tony interrupts. He's been feeling cooped up in his own home with his new guests, hence his current sojourn to the skies.

"Mr. Loki appears to be creating energy." Jarvis says. A small video feed of Tony's living room pops up in his HUD. Frigga is sitting regally on the couch, reading aloud to Loki, who, true to Jarvis' word, has some sort of green energy flowing around his fingers.

"Whoa," Tony u-turns in the air to head back home. "What do your readouts tell you?"

"I am unable to find a logical source," Jarvis says, almost sounding regretful.

Tony scowls, putting more throttle into his thrusters. He soars into the tunnel connecting to his workshop and garage, and steps out of his suit almost as soon as he touches down.

Upstairs, he finds Frigga still reading aloud and Loki, surprisingly, seems to be listening. They aren't picture books, either- Tony had half-jokingly bought some, and Loki had given them a cursory glance before shoving them at Thor in an almost patronizing manner.

Frigga has just started reading Macbeth, which Tony had suggested as a nod to his quip about Thor being 'Shakespeare in the park.'

"What, did you just get to double double, toil and trouble?" Tony arches a brow. "Come on, green thumb, we're going down to my lab."

"Green thumb?" Thor questions. "Is that not the Midgardian term for being skilled at gardening?"

Tony huffs and reaches out to grab Loki's wrist. Loki resists, as if he hasn't been tugging them all around.

"You wish to study his seidr?" Frigga asks with an air of disapproval.

"It won't hurt," Tony promises, though it hardly seems necessary. Loki may look frail now, but Tony's learned from Thor that space vikings are hard to hurt.

Loki takes Macbeth from Frigga and pushes the book against Tony's chest. He seems to show no preference whether his mother or relative strangers like Tony and Bruce read to him, but audiobooks elicit no reaction other than pointedly leafing through a paper book.

Tony doesn't take the book. "I don't have cauldrons down there, but sometimes there's fire. Can you make fire?"

"Loki first cast flames when we were children," Thor says, as if it's hardly impressive, and recounts a tale of Loki shapeshifting into a snake, only to shift back to himself to startle Thor.

Frigga looks exasperated and fond at the same time. "I taught him many spells. He has such a thirst for knowledge, even now."

"Did he ever turn into a horse?" Tony asks, and Thor's lack of an answer is pretty telling.

Tony finally gets Loki down to his lab, though Thor has to assist his brother on the stairs. Thor sticks by Loki's side, trying to prevent Loki from picking anything up, but Loki still ends up breaking a circuit board after flinging it downward.

Thor starts to apologize, but Tony shrugs and gestures to his clawed, boxy robot. "Trust me, Dum-E breaks enough. Dum-E, sweep these up."

Dum-E's claw snags a broom, and the robot wheels over to clumsily sweep at the circuitboard shards. Loki pays no attention, eyes on the Mark II.

Tony, of course, can't resist suiting up to show off, but Loki barely reacts when the suit hovers, even reaching as if to tug Tony down. Once Tony lands, Loki grabs Tony's armored hand and moves it as if to slap Thor.

"It is not the Destroyer, brother." Thor frowns.

"That was him?" Tony asks, having heard about the large, animated armor that wrecked havoc in New Mexico around the time Tony was dying of palladium poisoning. "I guess if he tried to destroy an entire world..."

"He was not of his right mind." Thor repeats, defending the brother who apparently tried to kill him. Do they have the insanity plea where Thor's from?

"Come on, let's see some of your mojo. Can you do this?" Tony raises a palm and fires a repulsor at the wall.

"Sir, I don't believe encouraging destruction is the best course of action." Jarvis says in an almost put-upon voice.

The green energy dances around Loki's fingers, and the room quickly fills with an acrid odor, accompanied by smoke rising from the hood of a nearby Audi. Tony wrenches the hood open with an armored hand, and Dum-E sprays it liberally with the fire extinguisher. Jarvis helpfully opens the window to air the workshop out.

"What is this, engine burn and oil bubble?" Tony grouses, surprised to see an almost wicked grin on Loki's face, though it quickly disappears.

"You did encourage him to shoot an energy blast, sir." Jarvis quips.

"Yeah, but he didn't shoot anything." Tony looks down at the smoldering remains of the engine. Good thing he likes rebuilding them, which is what he spends most of the day doing. Loki remains a visitor in the lab, shuffling around and generally causing even more trouble than Dum-E. Several times, Tony places a tool down only to find it missing when he reaches for it again, or replaced with an incongruous object.

In less mischievous moments, Loki pages through Macbeth but does not seek his mother out to read it to him. Loki actually seems to enjoy Tony's banter with his AI, which is the most interest he's shown in a conversation.

Tony works well into the night, long after Thor and Frigga have retired to guest rooms. Loki remains in the workshop, having resisted Thor's efforts to lead him to bed.

Tony feels Loki watching him intently, and when he looks through the holographic screen he's working on, Loki's pale skin is tinted blue.

Tony swipes the screen away.

"Monster," Loki hisses, once again wildly attacking his own face and arms, scratching lines into his skin. Jarvis alerts their guests. Any attempt Thor makes at calming Loki down only sets him off further, and even Frigga struggles to calm her son as he rages.