Stingray City. Ellen Prager

water in Florida, and his heart was hammering. Ryder and Sam popped up nearby.

      “Okay, we did it,” Sam said, her teeth chattering. “Let’s go back.”

      “Nah, let’s go farther out,” Ryder insisted, staring at Tristan in a silent dare.

      “You are seriously twisted,” Sam countered, starting to turn back toward shore. She paused. “Hey, what’s that?” She pointed to a dim, blue-green glow some twenty yards farther offshore and a little to the left.

      “Let’s go check it out,” Ryder suggested, taking off.

      Tristan and Sam looked at one another, shrugged their shoulders, and followed. As he swam, Tristan began to warm up. His eyes also began to adjust to the night’s darkness.

      Whatever the glowing thing was, it was about ten feet down and sort of spherical. The three teens dove and hovered close to the shimmering orb. Tristan watched as Sam reached out to gently touch the jellyfish’s bell, staying well away from its hanging strings of sting. The bell sparkled blue-green. As Sam pulled her hand away, Tristan realized that it too gave off a faint, luminous, blue-green glow. He looked at his own hands. They were shimmering too. He swam to the surface.

      “What’s going on with our hands?” Sam asked, staring at her glimmering hands. Then they looked at their legs, which had also begun to faintly glow blue-green.

      “Whoa!” exclaimed Tristan. “We’re bioluminescent.”

      “Awesome,” Ryder added.

      “Let’s go back and show the others,” Sam suggested. “Must be another effect of the new pills. Very cool.”

      “Nah, let’s stay out here,” Ryder said. “It’s not even that cold.”

      “Yeah, actually, that’s kinda strange,” Sam noted. “We should be freezing by now without wetsuits.”

      “I’m liking these new pills more and more,” Tristan said, thinking that in addition to now being glow-in-the-dark, the newest pills must also be why he had warmed up so quickly.

      Sam ducked underwater. Tristan heard a sort of clicking noise. Seconds later, Sam popped up and pointed seaward. “The kelp is messing with my echolocation, but I think there’s something out there.”

      Tristan squinted, trying to see where she was pointing. “Where and what kind of something?”

      “Something kinda big,” Sam answered. “I think it’s tangled up in the kelp.”

      Tristan was feeling warm and more confident. “Let’s go check it out.” Without waiting to see what the others would say, he swam toward the forest of kelp that lay offshore. Ryder followed. Sam paused, but soon she too headed farther out into the darkness.

      As Tristan got closer to the kelp, he could see that something pretty big was caught up in it, about fifteen feet down. Whatever it was, it was wrapped tight in a tangle of the rubbery seaweed and struggling to get out. Tristan dove, pushed a few pieces of kelp out of the way, and held up his hands. The faint glow from his skin provided just enough light to see what was there. But what was a scuba diver doing alone at night in the kelp—and without a light?

      Tristan waved his hands at the diver, trying to get his attention. But the diver was too busy trying to get free of the seaweed to notice. Tristan reached out and grabbed one of the long pieces of kelp encircling the diver. The seaweed was slick and slimy, making it hard to hold onto. Tristan felt the kelp brush against his legs. He kicked at it while trying to pull at the kelp trapping the diver. Seaweed encircled Tristan’s knees. Another piece began to wrap around his neck. Tristan’s pulse quickened. He stopped trying to help the diver and began pushing at the kelp now wrapped around him. But his movements only seemed to make it worse. The more Tristan struggled, the more entangled he became.

      Tristan twisted and turned, trying to slip free of the kelp. It wrapped tighter. On the verge of panic, Tristan felt a tap on his shoulder. He jerked around. Sam was beside him, signaling for him to calm down and stay still. Tristan forced himself to stop moving. Sam then began pulling the slick fronds of seaweed off him. Soon the kelp was loose enough for Tristan to wiggle free. He shot gratefully to the surface, where Ryder was waiting.

      “Thanks,” Tristan said to Sam. “There’s a scuba diver down there stuck in the kelp. I tried to get him out, but started getting tangled up myself.”

      “I noticed,” Sam said with a smirk. “What should we do?”

      Ryder shook his head. “If that dude’s air runs out, it’s curtains. Over. He bites the big one.”

      “Yeah, he drowns. We get it,” Sam said.

      “Maybe together we can pull him up out of the kelp,” Tristan suggested.

      “Let’s try it,” Sam said. “But be careful. Don’t kick or move around too much, or you’ll get trapped too.”

      “Yeah, no joke,” Tristan added.

      The three teens dove down and hovered near the struggling diver. Tristan again tried unsuccessfully to get his attention. He and Ryder each then grabbed an arm. Sam took hold of the top of the diver’s scuba tank. Together, Sam, Tristan, and Ryder kicked hard for the surface. The diver began to rise. They went up about two feet before the kelp sprang back like a giant rubber band, pulling them and the diver back down. The diver stopped struggling. Tristan let go and went to the surface with the others.

      “Now what?” Ryder asked.

      Tristan shook his head. He was thinking, wishing his brain would come up with a brilliant idea or even a passably decent one. Nothing.

      “Hey,” Sam said. “Maybe we can use Hugh’s new pocketknife thing to cut through the kelp.”

      “What?” Tristan asked.

      “Dude, remember earlier? Hugh was showing us the new tool his mom sent him,” Ryder said.

      Since Tristan hadn’t been paying attention to Hugh earlier, he just nodded like he knew what they were talking about.

      “You’re the fastest, Tristan,” Sam noted. “Swim back and get it. We’ll stay out here so you can find your way back.”

      Without saying another word, Tristan sprinted for shore, kicking hard. About halfway to the beach, he nearly ran face-first into a shark cruising along the coast. Both shark and human stopped short. The startled shark stared at Tristan. Sorry, Tristan muttered before continuing on. He then looked back at the shark, thinking about its pointed snout, big black eyes, and wide body, at least as much of it as he could see. And then he knew—it was a great white! Wow, Tristan thought, I nearly had a head-on collision with a great white shark. No one will ever believe it.

      At the beach, Tristan ran from the water to where Hugh and Rosina sat anxiously waiting on some rocks. He hurriedly explained the situation out in the kelp. From his pocket, Hugh removed the mini-pocketknife tool. He handed it to Tristan, who then dove into the water and raced back toward the two specks of faint light bobbing in the kelp bed. As he swam, Tristan kept an eye out for the great white, wishing he could’ve at least talked to it.

      Tristan, Sam, and Ryder dove down to again try to free the diver. Staying calm and moving as little as possible, Tristan opened the small knife blade in Hugh’s tool. He then quickly began cutting through the kelp. As he sliced, Sam and Ryder carefully pulled the seaweed off the diver. Several breaths later, the diver was sufficiently de-kelped and rose to the surface. The man spit out his regulator, gasping for air. “Oh man, thanks, whoever you are. That was close.”

      “Who are you, and what the heck are you doing out here?” Tristan asked, thinking, This guy is even crazier than us.

      It took a few minutes before the man could answer. “Same could be asked of you,” he said, breathing hard. “And how come your skin is glowing like that, and where are your wetsuits? You must be freezing.”

      “Uh, yeah, we’re freezing,”