Why was Snape able to use the Headmaster's office in Deathly

Severus Snape Drives the Entire Harry Potter Saga

How did Snape learn when Harry was to be moved in Deathly Hallows? - Quora

Harry Potter and the Deathly Hallows: Part 2 (2011) - Alan Rickman as Professor Severus Snape - IMDb

Snape: First Instinct is to protect the students from a Werewolf (expanded in comments) : r/harrypotter

Why did Snape search Grimmauld Place in Deathly Hallows, the time he took Lily's picture and signature? If he was on the good side, why would he search the place? - Quora

Why did Snape say always? - Quora

In Harry Potter and the Deathly Hallows pt. 2, Snape is still helping the Order of the Phoenix when he re-directs McGonagall's spells to the Death Eaters behind him : r/MovieDetails

Why was Severus Snape so reluctant to fight Minerva McGonagall in 'Harry Potter and the Deathly Hallows – Part 2'? - Quora

The Headmasters Office, spoil by NicoPony on DeviantArt