Picture this: You're nine years old and planning a mutiny against your teacher. What you're going to need is some kind of pirate captain to help you lead the uprising and make it properly scary.

Enter Johnny Depp. According to BBC News, the actor dropped in to Meridian Primary School in Greenwich, England, on Thursday after receiving a letter from a student named Beatrice. She had written to his "Pirates of the Caribbean" character, Captain Jack Sparrow, asking for help in leading the revolt against her instructors.

"Normally we're a right handful, but we're having trouble mutinying against our teachers," Beatrice wrote. "We'd love it if you could come and help."

Depp, who is currently filming "Pirates of the Caribbean: On Stranger Tides" at Greenwich's 17th-century Old Naval College, arrived in full Sparrow regalia and addressed the students in character at an assembly.

Accompanied by other costumed castmates, Depp read Beatrice's letter and performed as Sparrow for 15 minutes, singing pirate songs and dancing a few dead-man's jigs before counseling his pen pal that a full-on mutiny might get her into trouble.

Beatrice later told "London Tonight" that Depp "gave me a hug and he said, 'Maybe we shouldn't mutiny today, 'cos there are police outside monitoring me.' "

After the detour, it was back to work for Depp. He's headlining the fourth installment of the billion-dollar franchise alongside new co-star Penelope Cruz, who plays his potential sweetheart and the daughter of his nemesis, Blackbeard (Ian McShane).

Check out everything we've got on "Pirates of the Caribbean: On Stranger Tides."

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