Samantha, a true friend to the wild horse called Phantom, is torn when Jake, her partner in a charity horse race, loses the wild pinto filly he had planned to train to the stallion.
When a terrible blizzard traps the Phantom Stallion's band, Sam is afraid that they will be captured and is determined to help them stay free for good.
After the filly she saved in Nevada arrives at her grandfather's Hawaii ranch, Darby realizes the horse is in bad condition and she must try and save it.
Uncertain of her horsemanship, Darby starts to see a mysterious horse prowling the grounds of her grandfather's ranch at night and begins to wonder if it is the legendary Shining Stallion of Hawaii.
Seventeen-year-old Gwen is returning to her childhood home by the sea where she once had a strange encounter with a boy who whispered to her and disappeared.
Darby visits her great-grandmother, a healer who lives in the rain forest, connects with a wild mustang, and tries to mend the relationship between her two best friends, which was broken by a secret tragedy.
Samantha does not know what to do when her new friend Nicholas, a boy traveling cross-country on a Gypsy Vanner mare while learning about his gypsy ancestry, is suspected of being involved in the theft of a mustang.
Samantha's friend Ryan becomes determined to recapture his lost horse, Hotspot, who has been running free with the Phantom Stallion's herd, and Sam is torn between helping Ryan and staying at home where she knows she is needed.
