Disclaimer: The Avengers are not mine, but Marvel/Disney's. Any operations medical or military may have been written using research and some artistic license. If there are inaccuracies, no offense is intended.

Stark Tower, several days later…

"Why do I have a SHIELD agent in my ceiling?" Tony asked as he walked into the common room. "Do I need to be worried? Is he doing some sort of uber-paranoid weekly bug sweep or something?"

"He's probably checking for guinea pigs. It's a habit for some field agents, though I'm surprised it took him this long to get around to it," Natasha replied calmly from her place at the large kitchen table, firmly focused on a magazine. She looked up at the other agent sitting at the table. "This one, Coulson."

Coulson took the magazine which appeared to be a fashion catalog of some sort. "I'll get with Logistics. I'm sure we can get it altered in about a week. Maybe two, depending on the material."

She nodded in approval as he made notes.

Tony appeared confused. "Guinea pigs. He's looking for guinea pigs in my vents."

"Don't think too much about it," Coulson replied with an air of resignation. "He's been at it all afternoon. Just let him get it out of his system now, or you'll be hearing thumps in your ductwork all night."

"Does he do this every time he stays somewhere?" the inventor asked, giving the ladder a wide berth as there was a loud thump, followed by a rather creative curse.

Natasha nodded. "Only if he stays more than a week. It's a quirk, Stark. Nothing more."

"Sir, I had reminded you that a pest inspection was due last month," Jarvis reported. "Agent Barton has kindly offered to perform this service as well as a manual sweep for listening devices, which he advises are also classified in the unwanted pest category."

"Can't argue with that," Tony replied with a shrug.

"Indeed, sir. I prefer to consider it killing two birds with one stone. Though, an extermination company has been contracted to perform the inspection on the rest of the less secure floors underneath the common areas, as there are far too many floors for one person to inspect."

Clint breathed a sigh of relief as Jarvis ran interference. "Nice save, Jarvis."

"It is my pleasure, Agent Barton," the AI replied politely, his voice emanating from the tablet speakers. "I do trust that you will be kind enough to inform myself or Mr. Stark if any unwanted pests are located?"

"Consider it a promise," Clint replied quietly, thanking Stark's paranoia for the soundproofing within the vent and ceiling areas. He still couldn't believe the AI was letting him go behind Stark's back with his security upgrades. "I'm surprised you were willing to cover me on this. Aren't you programmed to tell him everything?"

"Only when the information is pertinent to the situation at hand or is specifically requested," Jarvis explained dutifully. "Based on an analysis of the recordings from the SHIELD database, the chances that the incident at the PEGASUS facility could have been avoided increase dramatically with the inclusion of arcane protections. I am merely allowing a required improvement to the current Tower defense design. Mr. Stark has not forbidden any such measures yet."

"Ah," the archer replied. "It's better to ask for forgiveness than permission."

"Indeed, Agent Barton. Though, I would suggest that you consider the option of disclosing the presence of the arcane sigils to Mr. Stark once the inscriptions are completed, sir. He may take the lack of reporting as a deception."

"Fair enough. I'll talk to him about it once I'm convinced he won't have me committed." Clint set the laser inscriber down, pressing firmly and pressing a button that would activate the suction cup that would hold it still while it worked. "Let's get this over with. Monitor the inscription depth, please – let's keep it to about a millimeter. We need it etched in permanently but we don't want to carve a hole in the place."

"Monitoring. The operating instructions within the laser should account for any discrepancies in the pattern, but I shall make adjustments if needed for any impurities in the sheet metal."

"That works for me. Now, three…two…one, and mark."

Clint lowered the polarized safety classes over his eyes and pressed a control on the device's remote, activating the preloaded pattern. A thin blue laser flashed outwards, skittering in a rapid pattern over the metal surface. A slight hiss accompanied the scent of burned metal as the ornate sigils took form.

While he wasn't sure whether or not Dr. Strange had been humoring him in an effort to ease his worries about encountering a being like Loki again, he didn't see the harm in adding an extra layer of protection to the Tower. The sorcerer had made it clear when he gave Clint the book of protective magics that he wasn't sure if they would work, since the archer wasn't a practitioner, but he had thought it worth a try.

It couldn't do much more than stop an invader as he wasn't able to modify it on the fly to do much else, but Clint supposed it was better than nothing. The team in the Tesseract hangar back at Pegasus had been helpless to stop Loki, and if he could put as many roadblocks as possible in the bastard's path this time, Clint considered it a win. At least it could buy time until one of the heavy hitters could be brought in.

Provided the damned thing worked.

He pulled out the new Stark Industries tablet that Pepper had given him, opening a file containing the building schematics. She had told him to use it as he saw fit when working with Jarvis, along with handing him a contractor packet that he had dropped by SHIELD Legal to check before signing off on everything. Fury hadn't had any problems with his "moonlighting" for Pepper, thankfully, though he suspected the Director thought it would give them an "in" with the company.

Clint had his scruples, however, and didn't plan on letting the organization have access to anything unless there was a damn good reason for it. He owed it to Pepper and Tony to protect their privacy after they had opened their home to him. Jarvis too; after working with the AI for only a few weeks, he understood why Tony jealously guarded his programming.

Soon, the inscriber beeped, signaling that it had completed the pattern. Clint marked the file, noting the location of the "trap." It was one of several that he would be adding to each floor, each burned in with light into the ceiling and under the floor panels. Light was considered a powerful element, after all, and might hold up better than some of the other more traditional elements.

Clint hated all of this metaphysical crap. He would have been perfectly content to stay a skeptic if Loki hadn't shoved magic into his head and unmade him. Being skeptical had been safe…almost comforting in a way. Loki, however, had forced him to be a believer.

A large part of any ward or talisman's strength comes from the will of the wielder, Strange had told him. The more you believe in its strength, the stronger the spell will be.

"So, anyway, I thought I'd give this little guy a test run," he heard Tony explaining to the others, the inventor's voice drifting upwards.

Natasha's voice sounded unsure. "Clint warned you about the vacuum, Tony. He went through three of them, I think."

"This bot is designed with a fully functional, if limited command interface," the inventor argued. "I did some research, and lots of canines hate higher pitched motors – it's a frequency that's painful or something like that. I've modified it with noise dampening circuitry so that it shouldn't be a problem for the pooch. He'll hardly know it's there."

"Tony…it's a Roomba."

The inventor scoffed. "This is not a Roomba. Roombas are boring, round automated lint rollers whose only real option for personalization is a full product line of googly eyes. This is so much more interactive! See, he even has multiple attachments. Not to mention, he's got magnets to allow for climbing - what Roomba can empty its own catch bin?"

"This is not going to end well." Coulson was probably shaking his head.

Clint began packing up the inscriber, slipping it into his pocket. As he looked down, he heard a slight whirr as one of the small vacuum-cleaner bots that Tony had recently created to deal with Arrow's recent shedding problem activated. It zipped along the floor rapidly, making a beeline for the German Shepherd.

Uh-oh.

He had warned the inventor about Arrow's dislike of vacuums. There was a loud snarl nearby as the small bot rolled towards the dog, its cleaning attachment outstretched. It chittered excitedly as it attempted to vacuum Arrow's fur.

Clint's eyes widened as Arrow jumped to his feet with a panicked yelp. The bot gave chase, giving out a loud bloop as the German Shepherd backed away nervously. Every time the dog tried to escape, the brave little robot followed, most likely trying to clean up the largest source of fur: the dog himself.

"Wait – down boy!" Tony ordered, his voice slightly nervous. "Bad robot!"

The ladder began to shake as the tide turned, and Arrow let out a loud snarl. The bot let out a panicked squeal.

Clint cursed inwardly. "Stark – turn that thing off or he's gonna kill it!"

Tony muttered to himself, pressing a control on the small remote in his hands. "It's not responding!"

Apparently, hundred-plus pound dogs and ladders didn't mix well. As the German Shepherd lunged at the robot, it darted beneath the ladder legs. Arrow skidded on the tile, colliding with the tall, metal legs and sending it crashing to the floor.

The archer swore, twisting in mid-air as the ladder fell, trying to recover. He hit the floor in a crouch, his knees and ankles sending spasms as he landed. He hissed in pain, falling over as Coulson, Stark and Natasha hurried over. "Shit."

"Are you alright?" Natasha asked, concern showing in her eyes.

Clint groaned, pulling himself up into a sitting position. "Yeah. But the robot isn't."

Crack.

Arrow was hunched over, tearing at the insides of the robot. Small bits of circuitry were strewn on the floor, with attachments scattered amidst the torn plastic chassis. He growled again, ripping another chunk out of the machine.

Clint scrambled to his feet, moving over to the dog, who growled menacingly. "Drop it, Arrow. Drop it!"

The dog wagged his tail proudly, trotting over to meet Clint with the dismembered robot in his jaws. With a sigh, the archer tugged lightly, trying to get the dog to relinquish his grip. Arrow released the remains and ran back to the rest of the scattered pieces, barking at the others.

"Alas, Roomba, we knew him well," Clint commented sadly, holding up the chassis and looking into its front sensor. He sighed, turning back to Tony with a sorrowful look. "I'm sorry, man – maybe I can help fix it or something?"

Tony merely blinked and took the robot gingerly. He glanced from it to the dog, who was smelling the remaining pieces. Looking back up at Clint, the inventor grinned. "Challenge accepted."

Upon returning from Asgard for a short visit, Thor sought Clint out, finding the archer during his final ward placement in the gym.

"Agent Barton," the prince greeted jovially. "May I have a word?"

Bang.

Clint's head jerked upwards, slamming into the floor panel above him. "Ow!"

"My apologies," Thor said, reaching down to check on the archer. "I did not mean to startle you!"

"That's okay," Clint groaned, reaching up to take Thor's outstretched hand. He sat up, rubbing his forehead. "I didn't realize you were coming back so soon."

Thor smiled. "The return of the Tesseract, combined with Mjolnir's power has vastly sped up our ability to repair the Bifrost. Asgard's connection to the nine realms has finally been restored."

"That's… good, I guess," Clint replied, keeping his face carefully blank at the mention of the infernal cube.

"Verily. It will take time before order is fully restored to the other realms," the Asgardian replied with a regretful tone. "It would appear that Asgard's presence has been sorely missed. There are villains afoot on some worlds, and they have not been idle in our absence."

The archer nodded. "When the cat's away, the mice will play."

Thor chuckled quietly. "'Tis a clever phrase. I shall attempt to remember it."

"So, uh…your brother's still secure, right?" Clint asked hesitantly. "Please tell me you didn't bring him back with you."

"Of course not," the large warrior replied. "I would not be so callous as to suggest that he undergo the same punishment as I, when my father cast me down to Midgard for my own failings. I do not believe he has the temperament to learn the same lesson that I did. No, Hawk – he has been sentenced to the dungeons below the Royal Palace, never to see the light of day again."

Clint nodded slowly, his eyes lowering to the floor.

"But let us not speak of my brother," Thor continued. He placed a hand on Clint's shoulder. "How fare you now that the battle is over? Spells affecting the mind are no small matter."

"I'm…getting there." The archer knelt down with a wince, greeting Arrow as he trotted over. "This guy helped, believe it or not."

Thor eyed the canine, and then reached down to allow the dog to sniff his hand. "Yes, the Son of Coul was telling me about your new hound and the comfort he has brought you. We have always considered them worthy companions, and I trust this fellow is no different. Though, our hounds tend to be a bit…larger."

"Well, this lug's pretty big for his breed from what I've read, but there're larger ones out there. Just an overgrown mutt." Clint patted the animal. "Yeah, I mean you."

"I still fail to see how such insults can be taken as affection," Thor complained. "I fear the animal cannot completely understand your words."

Clint shrugged. "Maybe it's the tone. Animals can sense things like that – they know when you're actually pissed off."

"He seems to sense no ill intent," the Asgardian commented. "In fact, I dare say he enjoys it."

"We've sort of come to an understanding."

"I see."

The archer reached down to retrieve the floor plate, returning to the opening. Thor followed him, his head tilting to the side curiously as he spotted something. He held a hand in front of Clint's chest, stopping him from replacing the panel.

"What?" Clint asked, trying to hide any hints of nervousness. "I was just doing a pest inspection."

Thor arched an eyebrow. "You must have powerful rodents indeed, to warrant a protective rune network such as the one you have laid here."

The archer looked at the ground again. "It's nothing…"

"Nonsense," the warrior snorted. "There is no shame in it, friend Hawk. One can hardly blame you for taking such precautions after encountering one such as Loki." He knelt down, taking a closer look. "I must say, you have managed to inscribe the pattern perfectly. I did not know you were such a runesmith. Or, possibly, could it have been learned from my brother when you were in his thrall?"

"Uh, no – I kind of cheated," Clint replied sheepishly, pulling the inscriber out of his pocket. "It's a laser etching system. I took the pattern from a book and programmed it in. This little gizmo did the rest."

Thor's eyebrows perked up appreciatively. "Very clever. I take it this device can repeat the pattern perfectly, every time?"

"Every time. Unless it's broken."

"Our scholars would love such a device," the Asgardian commented, "if they were not so attached to their quills."

At Clint's quiet chuckle, Thor turned back to the opening. "Would you like me to charge the wards for you?"

"You can do that?" Clint asked, his eyes widening in surprise.

Thor clapped him on the shoulder, grinning. "Aye, my friend. While I may not have my brother's expertise, I was taught the basics of runes and other spells. You have already laid the groundwork with your inscription device - you merely lack the raw energy to truly empower them. I can provide that for you."

"But…why?" the archer couldn't help but ask. "This isn't your responsibility."

"Mostly, because I consider you and the others residing here brothers-in-arms," Thor explained gently. He called Mjolnir to him, and gently touched the sigil on the weapon. "But I will admit feeling some responsibility for your heightened sense of paranoia, as it was my brother who damaged your confidence. If some of my strength can bring you some level of comfort, then I shall gladly give it."

Clint watched as electricity began to gather around the hammer. "Uh, Jarvis –"

"I am activating the electro-static shielding around vital systems within the Tower," the AI reported. "You may proceed, Prince Thor, but please do try to keep any excess discharges to a minimum."

Thor touched the hammer gently to the floor, and then reached down with his other hand to touch the center of the ward. The pattern flashed once, as if it had been struck by a pulse before settling down to a neat, dark pattern.

Clint looked down, watching the occasional pulse of energy run along the etched lines. He blinked. "Cool."

Arrow whined, leaning against him for comfort. The archer could almost feel the hum of energy flowing throughout the other locations. He patted the dog's withers gently.

"It is done," Thor said proudly, smiling at his handiwork. "Your network should reach throughout the upper levels of the Tower."

"Network?" He looked at the larger man in confusion. "What network?"

"Your grid of warding runes. They were written in the appropriate pattern for the most effectiveness – in a sort of grid. Did you not know this before you selected their placement?"

Clint shook his head numbly. "I just sort of put them where it felt right. It just popped into my head."

Thor gave him a look of concern. "Perhaps there is somewhat of a residual effect from the Tesseract, my friend. Or some knowledge may have been gleaned from the link between yourself and Loki."

The prince drew closer, his expression growing grim as the archer's face fell. "Fear not, Hawk, for I will do my best to ensure that he cannot take control as he did before. You are not the only friend of mine that he has injured, and I aim to see that he cannot harm those I care about again. You have my word on that, Agent Barton."

"Thanks. I think."