Which 2005 film sees Harry Potter unwillingly chosen as a champion in the Triwizard Tournament, a dangerous magical competition between three wizarding schools, and ultimately witness the return of Lord Voldemort?

The 2005 film that sees Harry Potter unwillingly drawn into a perilous magical contest is "Harry Potter and the Goblet of Fire." In this installment, Hogwarts School of Witchcraft and Wizardry hosts the Triwizard Tournament, a long-dormant competition between three major European wizarding schools: Hogwarts, Beauxbatons, and Durmstrang. Despite an age restriction meant to prevent underage students from participating, Harry's name mysteriously emerges from the Goblet of Fire, binding him as an unprecedented fourth champion to a dangerous magical contract.

The Triwizard Tournament itself is renowned for its extreme hazards, having been discontinued centuries prior due to a high death toll among its champions. The revived competition involves three formidable tasks designed to test the champions' magical ability, courage, and intelligence. Harry, alongside fellow Hogwarts champion Cedric Diggory, and the champions from Beauxbatons and Durmstrang, must face challenges that include confronting a dragon, rescuing a hostage from an underwater realm, and navigating a treacherous maze.

The film reaches its dark climax during the final task, where Harry and Cedric simultaneously grasp the Triwizard Cup, only to discover it is a Portkey. Instead of returning them to Hogwarts, it transports them to a graveyard where Peter Pettigrew, under Lord Voldemort's command, brutally murders Cedric Diggory. Pettigrew then uses Harry's blood in a dark ritual, enabling Lord Voldemort to regain his full physical form and power, marking a terrifying and definitive return for the Dark Lord. This moment profoundly shifts the tone of the series, ushering in a period of open conflict in the wizarding world.