Carlie yelled at Chelsea. “Don’t come out any farther.” “No,” said Chelsea. “I’ll swim back with you.” “No!” screamed Carlie. “Go back, we’re getting caught in the tide!” But Chelsea stubbornly swam toward her, not turning around until they were both swimming side by side, both trying to get back to the shore. “You should’ve turned back,” panted Carlie as she paddled hard. “That was stupid.” “That’s my middle name,” said Chelsea. “You shouldn’t have wasted your energy.” “Just swim,” said Chelsea. So they swam and they swam, but they didn’t seem to be getting any closer to the shore. If anything, it seemed they were steadily going backwards, getting sucked out into the enormous ocean. Carlie tried to see if her friends had noticed they were missing, but she couldn’t even see the beach from out there. “I’m tired,” panted Chelsea. Her eyes were red and full of fear now. “What if we can’t get back?” “Just tread water,”
