A/N: Loads of thanks to tapion580, Nako13yeh, Sumi Anzu and Guest 1 for reviewing, and Rue as always for still being my beta 8D
Bang. Tony Stark sits up and asks out loud to the empty air:
'What was that?'
Bang...bang...With his ear close to the wall, he can almost feel the reverbations. Trying to determine which direction it's coming from, he moves slowly around the room. The handcuffs are thankfully off, but the cell compensates for it by being about the size of a shoebox, redeemed only by its inclusion of toilet facilities. Here, with S.H.I.E.L.D. no doubt watching his every move, he feels – bizarrely – a bit more secure. Completely devoid of privacy, yes, but safe in the knowledge that if anything bad happens to him or to Loki, there'll be a dozen armed operatives ready to intervene.
'Anyone wanna tell me what that is, or am I supposed to guess?'
In answer, the door opens and Agent Romanoff enters. She's wearing a loose, comfortable tracksuit and walking a little stiffly, as if trying not to pull stitches.
'Nat? You're up and about!' He could almost hug her. 'Wasn't expecting you.'
'I bounced back.'
'What's going on out there? Have we hit something?'
'Like what? A seagull?' she snorts.
The lights flicker, accompanied by a subtle shift in his sense of balanace and an unmistakeable feeling of weightlessness. He realises the Helicarrier is descending rapidly.
'Thunderstorm?' he guesses.
'Thor,' Natasha corrects him. 'We're making an emergency landing before things get out of hand.'
'Jeez, he sounds pissed. Should we be worried about that?'
'I would if I were you. I think he just found out what you did to Loki.'
'Oh.' Tony's throat tightens. Loki. He can still hear those piteous screams, feel the Asgardian's body quaking beneath his own. Squeezing his eyes shut, Stark tries to block out the shameful memory. 'Is he okay? Loki, I mean? I didn't...I mean, I didn't hurt him badly, did I?'
'He's alive,' Romanoff shrugs. 'What can you tell me about the bite-marks on his shoulders?'
'The what?'
'The bite-marks on his shoulders. Because unless the DNA results are lying, you put them there.'
'I...fucking hell, I thought...I thought it was just...'
'Just what?'
Just a blowjob. '...Last night we, er...got friendly. It wasn't planned or anything, it just sort of...happened. I didn't think I bit him.'
'Is that why Pepper left you?'
'No, that was unrelated...Wait, how do you know about that?'
'We're SHIELD. We know a lot. The same can't be said for Thor, though. You'd better have a good explanation ready for when he comes looking for answers.'
Bang...bang...bang...
'Is that why you're here?' says Stark bitterly, 'To help me learn my lines?'
'Actually, I'm here on business. They sent me to interrogate you. To uncover the facts, to get to the bottom of this investigation. Personally I don't see the point.'
'No?'
'No. Because I already know what the truth is.' She looks directly in his eye. 'This is all your fault.'
'What?'
'You orchestrated this. You planned it right from the beginning. That was why Jarvis didn't alert us when Thor was attacking Loki: because you tampered with him. You knew Thor was going to fly off the handle, you knew Loki was in danger, and you didn't want anyone to intervene. That's why you put them in the basement – the soundproof basement.'
Tony's mouth opens and shuts wordlessly.
'You wanted Thor to get in trouble. You wanted him to be locked up. You wanted him out of the way so you could be alone with Loki. And you knew the best way to accomplish that would be to paint Thor as a threat, an enemy.'
Natasha is walking closer and closer.
'But you didn't stop there. You wanted me and Bruce gone too. You encouraged me to take Loki out on that drive because you knew there would be an ambush lying in wait. You knew my life would be at risk.' She pauses. 'Or rather, Thanos knew. Because that's who I'm talking to right now, isn't it? You're Thanos.'
'That's impossible,' Stark finds his voice. More forcefully, he repeats, 'That's impossible. I had no idea what Thor was going to do, and I had no idea you were going to get shot! How could I?'
'No, you wouldn't remember. You wouldn't remember doing any of it, because it wasn't you who did it.' She halts a few feet in front of him. 'It was Thanos, using your body. The real question is...what are you doing on this ship? What are you after?'
Before Tony knows what he's doing, he lashes out. Somehow he moves faster than Black Widow does, striking her with a ferocity he never knew he was capable of and sending her flying.
'Shut your mouth! You think you have answers? You know nothing!'
He's still going after her, still filled with inexplicable hatred. He wants to silence her, to smite her, to obliterate her like the worthless, pitiful, loathsome sack of mortal blood and bone she is.
Next thing he knows, he's grabbed from behind and his head is wrenched to the side, exposing his jugular. There's a sharp pain in the side of his neck as a syringe is jabbed into it, followed by an overpowering sense of fatigue. His limbs go limp, and he's unconscious before his eyes even close.
'Are you alright, Romanoff?' Maria Hill asks as she lets Tony hit the floor. 'That looked like it was about to get nasty.'
'I'm fine,' Natasha lies through clenched teeth, 'Just a scratch. He's definitely not in his right mind, though.' She checks the unconscious body on the floor is still breathing, then says into her comm, 'I need a medic in Tony Stark's cell. He's out cold. Send someone to monitor him until he regains consciousness.'
Hill helps her to her feet. At that moment the power goes out, plunging them into darkness. They both wait for the emergency lights to come on, but nothing happens. The far end of the corridor outside is still illuminated by daylight from the windows, and they start to head towards it.
'Thor must've done something.'
'I don't think it's him,' says Agent Hill, 'Director, what's going on?'
'We've lost power. All power. We're trying to bring our systems back online but something's blocking us. We can't trace the source of the interference because our computers are unresponsive.'
'Foul play?'
'Your guess is as good as mine. Meet me on the bridge as soon as you can.'
'Are we still in control of the ship, sir?'
'Negative. The only thing keeping us moving is impetus. Pretty soon it'll be gravity.' A pause. 'According to Agent Choi, a signal was transmitted just seconds before we went offline. It was coming from Tony Stark's cell.'
Natasha and Maria look at each other. The banging from deep within the bowels of the ship is still audible, ever-increasing in frequency as Thor's rage intensifies.
'Well, Romanoff, I think Thanos just answered your question as to why he's here. He's going to crash the Helicarrier with everyone onboard.'
