When Star received his powers on his first birthday, he became the most powerful pegasus in Anok. However, many were afraid to follow him, and felt safer staying with their over-stallions. The rest unified with Star and formed River Herd.

But now a horrible plague threatens the five herds, and the heartless over-stallion Rockwing of the Mountain Herd has plans to kidnap Morningleaf, Star’s closest companion, and take back Sky Meadow. Star begins to question his ability to keep his herd safe, especially with the threat of Nightwing the Destroyer’s return-the pegasus who inherited the starfire before Star and used it for evil. As much as Star wants to rely on his friends again for support, he’s afraid of the starfire he’s inherited. Star can heal, but he can also destroy. And the question is, will his dark powers overcome him