After years of trying to regain human form and living in hiding, Voldemort finally returns in Goblet of Fire, aided by his loyal henchman Peter "Wormtail" Pettigrew (Timothy Spall). Using Hogwarts' Triwizard Tournament to transport Harry to a cemetery where Voldemort's father is buried, the Dark Lord and Wormtail use Harry's blood, Wormtail's flesh, and a bone from Voldemort's father's grave, restoring the most evil wizard in the world and granting him his full powers once again.
However, there's one super confusing thing about this whole process: how does Voldemort get his wand back? In this Reddit thread, some fans try to get to the bottom of this problem, but ultimately, they come up short. Presumably, the Dark Lord dropped his wand when he was inadvertently destroyed by his own curse, and there's no way he could have carried it around with him while he was living as an evil spirit in an Albanian tree trunk, where he spends a full decade waiting to attack Harry again.
Certainly, Wormtail, Voldemort's most loyal servant — who handed the Potters over to his master to save his own life — could have picked up Voldemort's wand and kept it throughout the years. However, while in hiding himself, Wormtail lived as a rat (masquerading as the Weasley family pet, Scabbers), so where exactly would he have carried the wand? It's also possible that Wormtail hid the wand somewhere safe for over a decade, but series author J.K. Rowling has never clarified this point one way or another, nor have any of the movies.
This plot hole aside, all of the Harry Potter movies are available to rent or buy on major platforms now.