Theodore opened his mouth to answer, but paused. "Probably best that you don't know," he said, a bit regretfully. "I don't have a way of getting you out of here, so you'll have to..." He trailed off, unable to finish the sentence aloud. "I'm here to help."
He lifted the vial to Neville's mouth again, making sure he drank the whole thing. Then he set about doing what he could for Neville's physical health, which wasn't much. After a few moments of working in silence, he had managed to repair most of the muscular damage to Neville's shoulders and arms, though it was only temporary. He was staying in those bindings, so the weight of his body would cause more damage over time.
After that, he paused. "What hurt most, before I gave you the potion?" he asked. He was doing this a bit out of order, but he'd wanted to make Neville's pain go away enough that he could actually speak to them.