Three warriors asked the sun to grant them wishes of immortality to protect their people forever. One was turned into a merman, another was turned into a tree, and final warrior was turned into a stone.

Juniper Sawfeather has learned there is truth to this American Indian legend. She knows how it connects the mermaids she saved from an oil spill to the ancient spirit that trapped her in the branches of an Old Growth tree. Now she wants to find out if the final part of this legend is true: that some kind of magical stone exists. A lone mermaid finds her and shares a vision of a cliff along the ocean shore. This must be the place, and June knows she needs to find it.

Tragedy happens when June and her boyfriend, Carter, join her parents on a mission to the San Juan Strait to collect evidence of construction run-off pollution, and they are attacked by a killer whale. June is convinced that the killer whale was led by mermaids, and she is desperate to find out why they attacked and where they are hiding. Once again, Juniper is on a heroic mission, the most frightening adventure yet. A thrilling ending to this award-winning trilogy!