In this fantasy film directed by Chris Columbus based on the book by J.K. Rowling, Rickman plays the mysterious teacher, Severus Snape, who seems to be out to get Harry and his friends, but has the complete trust of the headmaster, Albus Dumbledore. Co-starring Emma Watson, Dan Radcliffe, Tom Felton, Rupert Grint, and Maggie Smith.
My [filming] was always contained to seven weeks of the year. The rest of the time I was making other movies or directing. But as soon as I put that Snape costume back on, I sort of go, ‘Oh, yeah…I know you.’