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The Battle at Hogwarts is the main event They get caught by the snatchers/deatheaters before they break in.

No, Harry, Ron and hermione do NOT get caught by the Death Eaters in Hogsmeade because Aberforth Dumbledore, who is the barman at the Hog's Head saves them. He also has the only access tunnel into Hogwarts cre4ated for the Room of Requirement. Their entry into Hogwarts to find the Ravenclaw Horcrux is what triggered the Battle of Hogwarts.