“I am the tether and the tether is me,” she said. “After the Great Sadness, Elysse changed. We all did. She wanted to protect the City. She was so afraid, so . . .” Her voice trailed off.

“Sorry, the Great what?”

Leela had hardly noticed the humans, she had been so focused on Sera.

“The Great Sadness was the biggest tragedy in Cerulean history,” Sera explained. “When two hundred Cerulean were massacred on the last planet the City was tethered to.”

“How horrible,” the human girl said as Sera made hasty introductions.

“Leela, this is Leo and his sister, Agnes,” she said. “They are the ones I told you about.”

“Thank you for helping my friend,” Leela said.

“You’re—wait a second, we can understand you,” Leo said, looking confused.

“Cerulean can always speak the language of the planets,” Wyllin said.

“I could not, when I first fell,” Sera said. “It was not until I arrived in Pelago that I was able to speak the human languages.”

Wyllin frowned. “Perhaps such a long attachment with no contact with the planet had crippled this ability.”

“No,” Leela said, her face darkening. “It is because the High Priestess has been siphoning magic from her people. To keep herself young and strong. She has somehow bent the circlet to her will, twisted its purpose to steal from us.”

Wyllin slumped against the fountain. “Moonstone is connective. It links our City to the planets and the Cerulean to each other. In days past, the stone was used by Cerulean to communicate, whether between City and planet or while on the planet itself. Like an external blood bond. We can read each other’s hearts, speak to each other by calling on our moonstone.”

“Like how I called on it to let me speak to you in the Sky Gardens,” Leela said to Sera.

“And how I could see my purple mother at the birthing houses,” Sera said.

“But the moonstone in the circlet is even more powerful,” Wyllin said. “It connects to all Cerulean. Imagine a blood bond so strong it can actually pull magic to it, absorb the power that lives within our blood. Instead of sharing, it only takes. That moonstone must be thrumming with Cerulean magic.” She looked at Sera. “But you were out of her grasp. Your magic must have replenished, grown strong like it is supposed to be while you were here on the planet.”

Sera looked down at her hands. “Errol was first because he was the easiest,” she said to herself. “And then Boris. And the humans last. When I was at my strongest. When I arrived in Pelago.”

“I beg your pardon, Ms. . . . Ms. Wyllin,” Agnes said timidly. “But what exactly is this place? The, um, the humans all seem to think it contains wealth or powers.”

Wyllin looked startled, but she spoke to Agnes with kindness.