Disclaimer: I don't own The Avengers or Doctor Who.
Technically only characters from Avengers are actually in it but a character from Doctor Who is referenced.
Tony was welded into place a cage around Loki. Loki had a nice cage, but he had trapped Thor in it and sent it flying. Thus, him having to weld Loki a nice cage that hopefully was strong enough so that the crazy, strong Asgardian couldn't get out of it. Inside the cage that was so far part heavy glass and part metal, Loki was sitting on Tony's work bench which the raven-haired being had dragged off to the side so that he was resting against the cell. His long fingers were against a metal section of the wall and steadily drumming against it. It was a strange pattern, four quick beats then a short pause, but he kept doing it again and again. He had been doing it ever since Tony had started working on the cage. Loki had been silent for awhile except for the drumming and Tony assumed he was pouting that he had lost the invasion which he was pretty sure that the crazy Asgardian had thought was impossible. The drumming was starting to bug him.
"Can you hear it?" Loki suddenly asked out of nowhere, sitting up from the wall and looking at him intensely.
"Yeah," he said and saw the raven-haired Asgardian eyes light up for a moment "it's pretty hard to ignore," he said looking pointedly at Loki's fingers. The Asgardian looked down and his fingers and then looked back up annoyance clear in his eyes.
"No can you hear it?" Loki said like that made it much more clear.
"I hear your fingers," Tony said started to get passed annoyed into the angry category. It didn't take much to do that though. The guy, being, Asgardian or whatever he was, had only hours ago flung him out of his tower with the intent to kill him. As Tony spoke Loki got up from the bench and made his way to the where Tony was. The look in his eyes was intense like the crazy guy needed him to say yes. The brunette looked warily at Loki. If he made any other move that he could even consider to be aggressive, if he so much as licked the glass that was between the two of them, he'd get the other Avengers back here. But not long after he finished speaking Loki visibly deflated and went slowly back to his workbench, like the genius had just told the Asgardian that his dog had died.
"He said that no one else could hear it,"
"Who said that no one else could hear it?" he asked despite telling himself that he was probably playing into a trap
"The voice. I was falling and he was there, he was the only thing I could hold onto," he said staring down at his fingers that had started drumming again. For a second Tony believed him but he shook his head. This guy was great at manipulating. This had to be some part of some contingency plan now that he had gotten caught since the raven-haired being was going back to Asgard. Loki would be out of his hair as soon as he finished working on the mechanism for the Tesseract that would take the two Asgardians back home and hopefully the billionaire never ever see the crazy gods face again. Of course, he had to finish the cage before he starting working on the mechanism for the Tesseract.
"Voices? Phantom sounds? If this part of an insanity plea you might want to work on it a little more," Tony said going back to welding. There was silence for a long moment before he faintly heard in a sad but also kind of wistful voice
"There was only one voice and it's gone now... but he left the drums."