Complete story — includes the ending
In order to give Katherine permanent control over Elena's body, Nadia's friend Mia plans to cast a spell for which she needs to use Katherine's corpse. However Damon has already buried it himself, in the tomb where Katherine was supposed to have been buried alive in the 1800s. Katherine compels Matt to give her personal information about Elena so that she can impersonate her at Tyler's welcome home party, and hopefully learn the whereabouts of her corpse. Caroline reveals to Katherine (posing as Elena) that she slept with Klaus, which Tyler overhears and becomes extremely angry and hurt. Enzo brings Aaron Whitmore to Damon, who tells him to complete his killing streak and kill him (just like his parents and grandparents), however Damon declines. Katherine and Nadia are able to find Katherine's corpse, and then complete the spell. Later, Katherine (possessing Elena) breaks up with Damon, which angers Damon and causes him to attack Aaron in the final scene.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, The Vampire Diaries season 5. HTML formatting and reference markers removed. · Content license