Samus Aran is sent to another nameless planet after the events on Planet Aether. What was supposed to be a routine recon mission turns deadlier when she finds herself embroiled in a war on multiple fronts, especially one in particular: her own mind.
A meteor impacts the nation of Equestria, Planet Equis. Tranquility is quickly snuffed out when a poison begins to spread violently. The Princesses cannot combat this unknown threat, as no knowledge of it exists. Help comes from an unexpected source.