Axol has always known his place. As the familiar to Serina—mermaid, witch-in-training, and daughter of the infamous Sea Witch Melusine—he cleans up her spell disasters, cooks her meals, and tries to keep her out of trouble. Even after she gifted him with speech through magic, he’s still just her adorable pet. A talking axolotl. A servant. But from Axol’s perspective? He’s her guardian. And he’s terrified.

Serina may be sweet, but she’s reckless, spoiled, and entirely too much like her mother for comfort. Melusine once tried to conquer the Kingdom of Atlantis, and Axol fears Serina is one bad decision away from following in her footsteps. He’s resigned to watching over her from the shadows—until the day she drags him to MerMage Academy for Bring Your Familiar to School Day. That’s where everything changes.

In Astronomy class, Axol discovers something that shakes his entire world: a sea of stars, a moon that whispers secrets, and—most ridiculously—a rabbit that supposedly lives there. For the first time in his life, Axol dares to dream of something beyond serving Serina. He wants to see the stars. There’s just one small problem. Well, several.

To reach the surface, Axol will have to:

Steal a telescope from Morvo, a dangerously hangry eel familiar.

Trick a purrmaid named Minette into handing over a shape-shifting potion.

Learn a light spell strong enough to blind a monstrous anglerfish lurking in the depths.

Somehow not get eaten in the process.

But when Axol finally takes the potion, turning into a merman for the first time, his plan takes an unexpected turn—Serina sees him. And, of course, she’s instantly suspicious. Panicked, Axol blurts out a name from his favorite old hero tales: Lancelot. Now, as "Lancelot," he finds himself stuck escorting Serina to The Pirate and the Moon Rabbit Dance—a ridiculous high school event he wanted absolutely nothing to do with. It should be simple. Get in. Get out. Try not to blow his cover.