In 'Twilight Eclipse', Bella Swan navigates complicated relationships with Edward Cullen and Jacob Black while uncovering secrets about werewolves and vampires. The story revolves around an impending conflict between the Cullen family and a group of rogue vampires created by Victoria, who seeks revenge for James' death. Ultimately, the Cullens ally with Jacob and his werewolf friends to combat the growing vampire threat, leading to intense confrontations and revelations about their histories.