The 75-year-old actor, known for playing Gandalf in 'The Lord of the Rings' and 'Hobbit' films, visited the Chew Valley School, said The Hollywood Reporter.
"In your preparation for your examinations, if you don't do your revision properly, do you know what will happen?" he asked the students. When they asked him, "What will happen?", he delivered Gandalf's epic line, "You shall not pass!"
The students enjoyed his impromptu performance, breaking out in a round of applause.