Hiccup fulfills his dreams of creating a dragon utopia and rules it alongside Astrid. When the sudden appearance of female Light Fury coincides with the darkest threat their village has ever faced, Hiccup and Toothless must leave the only home they’ve known and journey to find the mythical Hidden World before a hired tyrant named Grimmel finds it first. As their true destines are revealed, dragon and rider will fight together—to the very ends of the Earth—to protect everything they’ve grown to treasure.

In 1995, on the Kree Empire's capital planet of Hala, Starforce member Vers suffers from recurring nightmares. During a mission to rescue an undercover Kree operative infiltrating a group of Skrulls, alien shapeshifters with whom the Kree have been fighting for centuries, Vers is captured by Skrull commander Talos and forcibly subjected to a memory probe. She manages to escape and inadvertently pilots a pod to Earth, crashing in Los Angeles. Vers discovers she was a U.S. Air Force pilot who was presumed dead in 1989. As the situation escalates, Carol Danvers becomes one of the universe's most powerful heroes as Earth is caught in the middle of a galactic war between the two alien races.