I felt a tug on my toe. It was my shrimpy new stepsister, Tish. With Tish circling me like one of Saturn’s rings, this Mexican vacation had been less than perfect.

Tish grinned. “Time to play water polo, Kevin.”

I groaned. Count on Tish to pick a game that was scheduled for the same afternoon everyone else was going to the dolphin show. Most of our families were in Mexico for my dad and Steve’s wedding. I would rather have hung out with my cousins, but I had promised Tish I would play water polo. No dolphins for me.

“Manuel said the winners’ prize is amazing,” Tish said.

I squinted at the Mexican sun from my spot in the shade. After a five-mile beach walk with Steve, skipping shells across the waves, my legs felt like cement and my feet were covered in blisters. Besides, I didn’t care about winning some T-shirt. I wanted to see dolphins.

Tish pulled on my arm. Cement legs or not, I had promised. I crawled from my lounge chair. I was rewarded with smiles from Dad and Steve from their nearby chairs.

I limped along as Tish skipped to the other side of the pool, where the activities director was tossing slippery green and blue gear at the kids in the pool.

Fabio handed a blue one to me. “A cap so everyone can tell which team you’re on.”

Great. Swim caps with floppy bunny ears.

At least my cousins weren’t there to see me wearing a blue bunny hat. I slipped on my cap and jumped in, immediately wishing I hadn’t. The water stung the blister on my heel.

Tish wore a blue cap like me. No surprise there. Of course she’d make sure she was on my team.

She giggled. “I wish Aunt Eva was here to take our picture. You look cute in bunny ears, Kevin.”

Camera-crazy Aunt Eva absent? I’d call that a good thing.

“We get to use two hands to pass the ball here. In real water polo you only get to use one hand.” Last month Tish had joined a swim club that played water polo. She already thought she was an expert.

“And real water polo is played in deep water. At least this pool isn’t deep.” Tish hopped up and down, her chin barely above water.

I wondered about her definition of deep.

Manuel blew a whistle. “Blue on one side, green on the other.”

We went to the blue side of the pool. I lifted Tish out to sit on the side, then leaned on the edge.

A high school-aged guy tweaked one of the ears on Tish’s cap. “Greetings, fellow blues. I’m Ian,” he said. “I play goalie back home in England.”

“Excellent,” I said. “I’ll help you defend.”

Ian scanned the pool. “We may be in a right fix. Looks like we have a size issue on our hands, mate,” he whispered. “You’d better play forward.”

My stomach sunk. I was not exactly a good shot.

“Ready?” Fabio held a white ball in his hand.

I tensed, wishing I had a more reliable teacher than my new seven-year-old sister. It would be nice if I had a clue how to play. Or how I could get out of the water before I made a fool of myself.

Fabio blew the whistle and lobbed the ball into the center of the pool. Both teams kicked toward it, water splashing. I leapt forward too, but a tanned guy on the green team got there way ahead of me and shot the ball. Ian dove sideways and blocked it.

“Get down to their goal,” Ian yelled to me.

I swam toward the green goal. Maybe I wouldn’t blow it. Right. And maybe pigs would fly.

Ian tossed the ball to Tish. A muscled guy on the green team grabbed the ball. Tish held on, but Mr. Muscle lifted the ball, with Tish hanging from it, out of the water. Tish lost her grip and the green player swam off with the ball.

I looked at Manuel. I didn’t know the rules, but that looked plain wrong to me. “Hey! Is that fair?”

Manuel shrugged apologetically. “He touched only the ball.”

“Goal!” Fabio yelled.

Ian chucked the ball in my direction, but a green player shot out of the water like a torpedo and intercepted.

Moments later, Fabio yelled again. “Goal!”

We were getting creamed. Dad and Steve were standing at the edge of the pool, smiling encouragement, but neither one of them looked confident.

I looked at Tish, doing a good imitation of a drowning butterfly trying to get to dry land. Near Ian, another vertically challenged blue-capped kid treaded water, looking just as water-logged. Meanwhile, the green team all had their shoulders above water. Who made up these teams, anyway? I gritted my teeth. This was big time unfair.

Ian caught my eye, flung the ball across the pool to me, and I nabbed it. I had to act fast.

I aimed at an open corner of the goal, but my angle was off and the ball went out of bounds. Green ball.

I groaned. I needed to think of another way to score.

Soon enough, I had another chance. The ball soared my way. I intercepted and was about to pitch it at the goal, but the sun glinted off the water and blinded me, just like it had when Steve and I had skipped shells in the ocean. Skipping. That was it! I beamed the ball; it skimmed across the water and went in the goal.

“Goal!” Fabio yelled.

I grinned. Steve gave me a thumbs-up. Like skipping shells across the waves.

When I got possession again, I whipped the ball along the water surface. Score!

Last quarter, score tied, four to four.

“Thirty seconds left!” Manuel yelled.

As Manuel counted down the seconds, I caught the ball. I wasn’t going to let my team down.

The green goalie and both defenders loomed over me like a pack of gorillas.

“Nineteen, eighteen …” Manuel yelled.

Skipping or not, I’d never get through those guys. I noticed Tish, wide open, bobbing like a rubber duckie a yard from the goal. And at the perfect angle.

“Thirteen, twelve.…”

I faked a throw at the goal, then side armed the ball at Tish’s head. The ball skimmed the top of her head, changed direction, and…

“Goal!” Fabio yelled. “Blue wins!”

“Is that fair?” the muscled green player who’d picked Tish up earlier asked.

“Skipping the ball off another player’s head?” Fabio shrugged. “Don’t see why not.”

Cheers erupted from the blue team. Dad and Steve clapped and whooped.

Fabio waved. “Blue team, over here.”

I swam closer to Tish. “Is your head okay?”

Grinning, Tish tapped her head. “I never knew my head was a secret weapon.”

Ian swam over. “Nice play, mates.”

“Ready for your prizes?” Fabio asked.

I nodded. Who couldn’t use a new T-shirt?

Along with T-shirts, Fabio waved arm bracelets. “If your parents agree, tomorrow we swim with the dolphins.”

“What?” I said. “No way!”

The hotel photographer appeared. “A photo of the winning team, por favor.”

We bunched together, still wearing our blue bunny caps. I beamed. Too bad Aunt Eva wasn’t here to take a photo, too.

The photographer focused. “Ready? Everybody say, ‘Dolphins!’”

I put my arm around Tish. “Dolphins,” I said, “here we come.”