The sharks want Kappa dead, and time is running out for Prince Siren to save him. Queen Susca knows Siren doesn't have the courage to kill Kappa, and for the sake of the kingdom, she's willing to do the deed herself. As tensions run high, neighboring queens pay the sharks a visit to offer an alliance, and while they might just be the means of escape the two mermen have been looking for, it's unclear if they can be trusted.

Siren will do anything to get Kappa to safety--even if it means never seeing him again, and even if all Kappa wants is to stay by his side. Yet escaping the queen's spear will take all of Siren and Kappa's courage and cunning, and there's no guarantee they'll both make it out alive.

This beautiful graphic novel collects episodes 20-41 of Webtoon's Castle Swimmer and includes a never-before-seen bonus chapter featuring Kappa and Siren.