Peter heard her return thought, felt her moving closer. He could almost feel the burning in her legs from the exertion, and knew the guilt weighing on her mind. He wanted to try and reassure her, but this was no time for it. It wouldn't mean anything until she was there, until she could see him.
He held on to the connection, the rest of his mind focused on slow, steady breathing. Darkness had already filled his vision; he was hoping that he could hold off the hallucinations until Claire arrived. It would only worry and upset her more to know how many times he'd gone through the life-and-death cycle.
To the ground when you arrive. Look to the ground. His fingers edged precariously over the hole he'd made.
Rain kept trickling in, though slowly. There was a quarter-inch of water in his cavern. Another inch and it would be at his lips. Don't panick. Just keep the arm there, fingers against the pavement. Slows the amount of air being used, but also slows the water from coming in. Fingers on the surface; a show of where he was.