Meet Marissa, a caring, curious, and brave eleven-year-old girl whose summer stroll on a quiet beach becomes an epic adventure that pulls her into a mysterious undersea world. Lured by the simple sounds of a unique seashell, Marissa finds herself pulled into a battle between an ancient marine species and advanced life forms not of this planet. Her survival and only path home is that of legends as she befriends magical creatures and battles an evil nymph while in quest of a simple flower. The petals of the Neptius flower hold the answers and are the salvation for Marissa and an entire undersea universe.