An imaginative nine-year-old has trouble when she claims to have seen a sea monster in the bayou near her house and when she tries to protect her new friend whose harelip has made her the subject of malicious gossip.
Nine-year-old Marcie accompanies her brother and their Cajun friend Jake on a shrimping expedition whose near-tragic end teaches Marcie about more important things than shrimping.
The Water Realm, as well as the Human World, is reeling from the invasion of Croatoan. Aquarius, Bayou, and Coral’s lives are hanging in the balance, as Rachal tries to find a way to save them and stop Croatoan. Croatoan is on cloud nine since most of his enemies are dead and he is on his way to ruling the world. The only people standing in his way are Rachal Porter Moreau, her friends, and an ally turned enemy. But he has a few tricks up his sleeves they will never see coming. The race is on to stop Croatoan as lines are crossed, secrets unfold, and lives are changed forever. Who will survive as the final battle against Croatoan ensues?