"Hey, Dad!" Poseidon glanced up and smiled as his twin demigod children swam towards him. He noticed Triton scowl to his right and looked at him instead. Triton had his eyes fixed on the mosaic in front of him, but Poseidon could see the anger boiling under the surface.

"Ugh, he's here."

"Lou, be nice. He's family."

"Half-family."

"Lou…" Percy warned.

"Lou…" Louisa mimicked in a cruel imitation of her brother. The twins stopped on the other side of the mosaic, opposite Triton. The two-tailed, immortal merman glowered at them. Percy remained calm, but Louisa glared back. Percy nudged her, looking at her warningly. Louisa pulled a face and folded her arms. "What's goin' on, Dad? Ya interrupted our zombie killin' streak."

"Very sorry." Poseidon said unapologetically. "You two are our reinforcements."

"Father, we do not need those mortals!"

"Hey, less of the mortal shit, buddy."

"Louisa, we talked about what to say to whom."

"Yeah, that worked." Louisa grumbled sarcastically. Poseidon sighed and looked back at Triton.

"We need every fighter we can get, you know that."

"But these two? In an immortal battle?" Triton shook his head. "Father, they will not last long." Louisa made to say something angrily in retort, but Percy quickly covered her mouth with his hand.

"We'll be fine." Percy jerked his hand away. "You're disgusting!" He protested, wiping his hand on Louisa's sleeve. She stuck her tongue out at him. "Decontamination." Percy muttered.

"Dude, we're twins. My germs, your germs." Percy looked at his father- this is your fault, he seemed to say. Poseidon merely smiled. "Anyway," Louisa pointed at Triton, "Listen here, Tails, have ya seen us fightin'?" Triton didn't even get the chance to answer. "No, ya haven't. 'Cos almighty 'n' immortal warrior Triton is stuck in the sea while we," Louisa gestured at herself and her brother, "Can go wherever the fuck we like." Triton coloured.

"Watch your language, mortal." He spat the last word as if it were some horrible disease.

"Watch ya attitude, scum." Poseidon slammed the butt of his trident on the floor.

"Fighting amongst yourselves will not get the bigger fight handled." He said sternly. He glanced at the mosaic again as the doors banged open.

"Lord Poseidon!" A Cyclops bowed hastily. "Many of my brethren have been trapped in the forges! Some of Oceanus's monsters crushed the roof!" Poseidon rose.

"Tyson…" Percy started, looking at the Cyclops. The Cyclops hesitated and shrugged.

"I do not know." He said softly. Percy's shoulders slumped and he looked pained.

Percy remained silent, worrying about his little brother. Poseidon left, following the Cyclops. That left the twins and Triton studying the mosaic. "Right, we should go there." Louisa pointed at the outskirts of their father's kingdom, where the fighting was the worst. Triton scoffed and Louisa glared at him.

"You two should go there. Protecting the nurseries."

"Nurseries?" Percy looked at where Triton had pointed. "Like kindergarten?"

"All of the mer-people's offspring is raised and educated there."

"So, you want us ta protect midgets?"

"Lou, it's a good thing."

"Yeah, but look. There's a small army around them already- 'bout ten men deep 'n' fifty along. They've covered the whole block, see?"

"Oh yeah…" Percy mused. "So, we go there, then?" He pointed at the bigger fight.

"The farms will need some help. If they take out our food supply and act a siege, we will have some trouble."

"Farms are guarded too. Dad's thought of all this stuff- ya just want us out the way." Triton glowered at Louisa. Percy bit his lip, more interested in watching the collapsing forges as the mosaic version of their father battled to help those trapped inside. "Percy?!"

"Wha-?"

"I was askin' what'd ya think, but ya too busy starin' at pretty colours."

"I was watching for Tyson." Percy grumbled, his defensives shooting up and his temper rising. Louisa braced her shoulders and glared at him.

"You wish to fight in the worst of the battles, yet you fight amongst yourselves more than anyone ever will." Triton chuckled. "How pathetically mortal." Louisa's arm swung down in a blur and a flash of silver grazed past Triton's cheek, his immortal blood swirling in the water. Her knife lost momentum in the water and floated away, but she had dealt out harm in a warning.

"Ya wanna watch what ya say, brother dear, 'cos ya might say the wrong thing 'n' I'll be more accurate with ma throws." Triton glared at her again. Louisa returned it with a stronger, fiery glare.

Percy sighed, returning his attention to the mosaic. The mosaic-Poseidon had willed the water to remove all rubble and there were masses of Cyclopes swimming out from the ruins. Percy watched earnestly for his little brother, but there were so many Cyclopes, he didn't see Tyson.

Percy felt a hand on his shoulder.

"We'll find him, bro." Louisa assured. "He's probably found a quiet corner, eatin' peanut butter sandwiches 'n' talkin' ta Rainbow."

"I hope so."

"If not, he's smackin' uglies in the face with the big stick thing he loves." Percy smiled weakly. "He'll be fine, Percy, don't worry."

Triton watched the pair, bewildered as to how or why he was related to them.

Damn his- their- father...