“Is he always this full of himself?” Zeran asked, leaning against the wall beside Eleni.

“Yes,” Frankie and I both answered.

Eli crossed his arms. “Forget about Winston. I want to know how the heck the Lord of Shadows is so much more powerful than the celestials. I don’t get it.”

“The Lord of Shadows is a celestial,” Zeran reminded him.

“And he was the universe’s first child,” Eleni said, still staring blankly at the stone wall in front of the library. “He was born many millennia before the other celestials. Thus, he has been drawing strength from the universe for much longer.”

I frowned, my head spinning. A half-formed idea danced around the edges of my mind. No one was invincible, not even a celestial. What was his kryptonite . . . his Achilles’ heel? “So how do we break his connection to the universe?”

“I don’t think we can disconnect him from the universe,” Frankie said, taking her glasses off. She used her shirttail to clean the lens. “Everything is contained inside the universe. Technically there is no outside—like that actually defies logic.”

“Drop him in a black hole,” Gail Galanis suggested. She had wandered over from the group surrounding Winston. “My cousin did that to a lava-spitting monster that attacked the island of Crete.”

My friends gawked at Gail in disbelief until she told them that her great-great-great-great-grandmother was a Titan, though no one in her family could say which one.

Eli arched one eyebrow. “So you’re a godling . . . Wait, no, a demigod?”

“Not exactly.” Gail grimaced. “But I am immune to the effects of most magic.”

“Godlings!” said Oshun sharply. She’d suddenly appeared in the hallway in a halo of mist. “Return to your classrooms.”

Nana materialized beside her, and the two celestials swept toward the library. None of the godlings left—we watched Nana press her hands against the slab of stone blocking the library.

“Ollie, Ogun, and Shangó are inside,” Nana said, voice hollow. “They’re alive.”

Oshun let out a sigh of relief. “Thank the heavens.”

Nana frowned with her hand still pressed against the stone. “He . . . the Lord of Shadows is almost through the veil.”

“He dares break through in our sanctuary—a place of peace!” Oshun hissed.

Oshun was missing the bigger point. The Lord of Shadows had broken into the sanctuary because he could. It was his way of showing the celestials that they couldn’t stop him from entering the human world, not even when it was right under their noses.

“We have to reinforce the barrier,” Nana said, resigned.

“But . . . what about my brothers and Ollie?” Oshun asked. “We can’t just leave them.”

“No choice.” Nana shook her head. “They’ve bought us time.”

Oshun nodded reluctantly and pressed her hand next to Nana’s. Magic rippled across the stone slab in waves. The guardian mermaids’ iridescent tails shimmered as if they were absorbing the celestials’ power.