Natasha regained consciousness several hours later. She was concussed and in a lot of pain, using all her remaining energy she managed to drag herself over to Clint's side.
Neither of them spoke, neither did Tony or Steve; they were in a dire situation. They were completely trapped, Natasha was severely injured, and they had no idea where or in what state Bruce and Thor were.
Gavrok wanted information on how they became superheroes; he wanted the secret to becoming Iron Man, the history of Natasha's training, he'd probably been questioning Bruce on his experiments which resulted in the Hulk too. Information they could not afford to give him, information which if withheld much long; would kill them.
Clint didn't sleep at all that night, he checked over Natasha's injuries when she'd fallen asleep again; she had a broken wrist and several broken ribs, bruises covered her skin; shades of purple, black and blue. She'd been burnt, electrocuted and stabbed. Visible marks of torture were everywhere. Clint couldn't let her go through that again; he knew she'd never reveal her secrets; she'd never even really divulged much about her past to him, but Gavrok wouldn't give up, and Clint needed to make sure he failed.
The next morning Gavrok appeared once more, he strolled to the end cell and threw some photo's over to Tony, they were pictures of Pepper; her at work, her outside her home, her with her family. He'd done his research and didn't need to say another word to get his point across.
Next he unlocked Clint's cell and dragged Natasha from her position at Clint's side. Clint tried to fight, but he was still bound to the back wall; he begged and pleaded him to take him instead, but Gavrok said nothing; he bound Natasha's hands and feet, injected her with a sedative and slung her over his shoulder. On his way out he stopped in front of Steve's cell;
"Your team is suffering, dying, and you could stop it all..."
Steve glared at him from where he was slumped in the corner, now he had his attention
"Tell me about the super serum, help me recreate it, and i'll let the others go. Think about it..."
And with that, he left once more.