Timescape by Robert Liparulo

He kicked and kicked, waved his arms in the treading-water fashion he’d been taught. His head broke the surface. All he could do was gasp for air. He didn’t know how much more he could take. Going under without warning, without breath, time and time again. The short reprieves on the surface were too short, almost torture, teasing his lungs with air, his body with rest.
    â€œDad?” he said, and took a deep breath. He was afraid to say any more. He wanted his lungs to be ready, full for the next tug.
    He had to slip out of the ring. It was the ring. It was pulling him down.
    â€œGo with it, David,” Dad said in his ear. He was squeezing him close, pressing his lips right on David’s ear. “Next time it pulls you, go with it. Don’t fight it.”
    David jerked his head away. He looked into his father’s eyes. “I don’t understand. It’s under—”
    Water washed over his head, and blast it! if he didn’t swallow a gallon of the salty stuff. He’d promised himself he wouldn’t be caught off guard again. He kicked, pulled at Dad, but realized Dad was under too. They both struggled and fought, and eventually David felt the cold, cold night air on his face. He spat and breathed.
    Dad was there again, his mouth almost eating his ear. “Okay, okay. That one was a surprise,” Dad said. “Keep going when it takes you. It’s the portal; the items are showing us the way. Look . . .” He pointed.
    â€œW-w-what, the tablecloth, the doll?”
    â€œYeah,” Dad said, excited. “They were beside us a few minutes ago. Now they’re way off that way. We should have drifted with them, not in the opposite direction. The items tugged us to the portal. Go with it, Dae.”
    â€œBut . . . but . . .” David could hardly find the words. “It’s underwater !”
    â€œYes, but it can’t be too far,” Dad said. “The pull is strong. Swim toward it. Stop fighting it.”
    â€œYou . . . you go first,” David said. “I’ll hold on and follow.” He was scared and didn’t mind letting it show.
    â€œListen,” Dad said. He held David’s chin, pointing their faces at each other. “You go without me. Get home. I’m going to wait for Xander.”
    â€œNo!” David said. “I’m not leaving you. I’m not leaving Xander.” What was it with this family, always separating?
    â€œWe’ve been in the water, what, ten minutes?” Dad said. “I’m having trouble breathing, and I can’t feel my hands or feet. You have to be slipping into hyperthermia too, Dae. Maybe worse than me.”
    David had been too panicked by the constant dunking to notice. He’d chocked up his shallow breathing, his not getting enough air even when he was on the surface long enough to get it, as a side effect of swallowing so much water and being so scared. Hypothermia—freezing to death. Could be that too. His hands and feet had moved when he’d wanted them to, but that was only because they were attached to his arms and legs, heavier muscles that had not yet succumbed to the cold water. He flexed his fingers. They barely moved.
    He nodded. His teeth chattered so hard, he thought they might break.
    â€œAll right, then,” Dad said. “I’ll meet you back in the house.”
    David saw something on a swell over Dad’s shoulder: Xander! He was thirty feet away, swimming toward them. He kept looking up, getting his bearings. His arms pumped up and down—a shiny object still in his hand—and his legs kicked. The faint glow of a light somewhere caught the paleness of his face. His eyes sparkled blue, and David noticed his brother’s lips were nearly the same color.
    Xander opened his mouth wide to gulp in air, a plume of mist billowing out first. His bottom lip trembled so badly, David could see it quivering from that distance.
    â€œLook,”