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

Severus Snape - Wikipedia

Severus Snape's Biggest And Best Moments In Harry Potter Movies

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

Severus Snape, Villains Wiki

Do you think Harry, Snape, and Voldemort are modern allegories to the Peverell brothers we meet in “The Tale of the Three Brothers” in Deathly Hallows? - Quora

What would have happened if Hogwart's students had given Harry away to Snape in the Great Hall in Deathly Hallows? - Quora

Severus Snape Drives the Entire Harry Potter Saga

Severus Snape from Harry Potter Series

What kind of a relationship existed between Severus Snape and Minerva McGonagall? - Quora

If Ghost Rider used the Penance Stare on Dumbledore, Voldemort, Grindelwald, Snape, and other HP characters, what would the results be? - Quora