Woo! Two chapters in one night!

'Shit, Natasha! Stairs were invented for a reason, you know', Clint whispered to Natasha as they climbed up a vertical vent.

'Shut up, Clint. Only one more floor', Natasha grunted. She was climbing up by bracing her back against one side and moving her arms and legs up, almost like crawling. Clint had gone first, and was pushing himself up by bracing his arms and legs against opposite sides of the vent.

After another agonizingly long minute Clint reached a horizontal vent. With a grunt he maneuvered himself into it, feet first, and reached back to pull Natasha into the vent. He shuffled back awkwardly until his feet touched a grate. After a nod from Natasha confirmed that the room behind it was empty, Clint turned onto his back and kicked the grate, hard.

The first kick didn't do anything, but the second and third dented the grate, and the fourth kick made it fly away from the wall, hitting a coffee table. Clint and Natasha climbed out of the vent, hoping the noise hadn't alerted anyone to their presence.

Neither of them recognized the room, but a glance out the window showed that it was on the fourth or fifth floor on the north facing side.

'Come on. We need to get to the roof', Natasha said.

'Fantastic. You got another great plan for that?', Clint asked sarcastically.

Natasha shrugged. 'Elevator?', she replied.

Loki stood on the roof in the centre of the symbol Tony had spray painted. He began chanting in a low tone and a blue glow began to radiate from his body. After a moment Tony realised that Loki himself was turning blue. Cryptic lines appeared on his skin, and, when he opened his eyes, Tony saw that they were orange.

Tony's phone beeped, demanding his attention. He checked it distractedly, then swore. With one last glance back at Loki, Tony went inside and answered his phone.

'Fury. This isn't exactly the best time', Tony said as he paced the length of the room.

'What the hell is going on in there, Stark? Coulson's sent out a distress signal from your fucking foyer. Please at least tell me you have the Loki situation under control'.

Tony turned so that he could see Loki out the window. The blue glow had deepened and was more like a mist now, swirling around Loki's body. 'Well Loki is never "under control" per se, but I'm on it', Tony replied.

Out of the corner of Tony's eye he saw the lights on the elevator change as it rose. He swore under his breath and raised the phone to his ear again. 'I. . . I'll call you back when I get this sorted, Fury', he said and hung up on the Director. The phone rang again immediately, so Tony just put it on silent and threw it onto the nearest sofa.

'Jarvis. Who's in the elevator?'

The television blinked on, showing the footage from the security camera in the elevator. 'I believe it is Miss Natasha Romanov and Mr Clint Barton based on their physical attributes, gait and speech patterns, sir', Jarvis replied. 'I believe they entered through the vents again. However, I was under strict instructions not to disturb you, so-'

'Yeah, yeah, shut up Jarvis', Tony interrupted. He ran a hand through his hair in exasperation. 'What floor are they on?'

'They're on the floor below this one. Sir', Jarvis replied icily. 'They will be here in a moment'.

Tony swore again. 'Jarvis, black out any windows they could see Loki through', he said. Jarvis did so immediately, shielding Loki from Natasha and Clint's view as they emerged from the elevator.

'Hello, Tony', Natasha said. 'Fury's not very happy with you, you know. Something about five S.H.E.I.L.D agents - including Coulson - being kept hostage in your foyer. Not that you'd have anything to do with that'.

Review! I'm thinking this might be done in another couple of chapters (but I don't really know - I never planned on it being this long :P)