"Annabeth!" Percy called. He sounded really pleased with himself. Annabeth sighed and gave up her sunbathing to go and see what Percy wanted.

He and his sister were standing two metres apart. Percy held Tobias.

"What's the matter?"

"You've gotta watch this." Percy insisted, placing his son in the water. "Go to Lou." Tobias looked up at Lou with his big, innocent grey eyes. Percy carefully let go, but his hands hovered by Tobias's sides just in case.

Tobias kicked out. And again. He moved his arms wildly.

Annabeth grinned. Her son was swimming at seven months old.

When Tobias reached Louisa, she lifted him and held him above her head. He kicked his legs excitedly, gurgling happily.

Louisa waded forward and handed Annabeth the infant.

"Aren't you clever?" Annabeth praised, smiling.

"Ah!" Tobias agreed, kicking his legs with more enthusiasm.

"Hey, Annabeth?" She looked at her husband. "Wanna go on that?" Percy pointed at a blue tower. From it fled a zip wire that stretched to another, similar tower. The only difference was that the second tower had a flume. Those who stayed on the zip wire to the other side got to go down the flume. Those who let go early landed in the deepest part of the pool.

Annabeth studied it for a minute before looking at Louisa, who was twisting the water in the air.

"Lou, you don't mind watching him while we go on that, do you?" Louisa looked up, holding Annabeth's gaze for a second before looking at Tobias.

"Watch Squirtface?"

"Don't call him that!"

"Fine, I'll watch the Drool machine." Annabeth scowled at Louisa.

"Stop calling him names, Louisa."

"She used your full name. You're in trouble, sis."

"Oh, she'll get her 'revenge'," Louisa motioned quote marks in the air, "supposedly later. Ah, ya made my tower fall." Louisa pouted childishly before getting out the pool and taking her nephew. "No pooin' on me, ya hear?" Tobias had his fingers in his mouth, drool running down his chin and hand. He looked up at his aunt with those round, angelic eyes. Louisa sighed and returned to sit on the sun lounger (I still don't know what they're called!).

Five minutes after Percy and Annabeth joined the (suddenly) long queue, Tobias decided to stink. Louisa groaned. "Why'd ya have ta stink now?"

She got up, Tobias on her hip and the shoulder bag with the baby care stuff in over her shoulder.

Louisa had a problem.

She didn't know how to change a diaper.

Instead she went to get her brother. She stood near the bottom of the first tower and looked up, spotting Percy and Annabeth at the top of the stairs. They were laughing at something.

Louisa sighed. "Percy!" She shouted. Percy moved forward and looked over the edge.

"What's the matter?"

"He stinks!"

"Go change him then!"

"I don't know how!"

"You're a girl, figure it out!" Louisa scowled at him. Percy and a few of the other holiday makers surrounding her laughed. Louisa looked round, an idea forming. If she hurried she could get one back on her brother.

Thankfully, a kind old woman took pity on Louisa and showed her how to change a baby. She made to dispose of the dirty diaper, but Louisa stopped her.

"But, my dear, it's horrible. Why keep it?"

"If ya come outside, ya'll see. C'mon, Squirtface."

"Ah!" Tobias insisted, holding up his arms. Louisa scooped him up, balanced him on her hip. She held the dirty (and incredibly stinky) diaper in her left hand. The old woman followed her out, curious.