Michael Caine writes in his new memoir, “Don’t Look Back, You’ll Trip Over: My Guide to Life,” that he was actually “terrified” of Heath Ledger on the set of Christopher Nolan’s “The Dark Knight” (via NME). Caine played Alfred Pennyworth in Nolan’s Batman trilogy, with Ledger joining the second installment as the Joker.

“The smeared makeup, the weird hair, the strange voice. It was chilling,” Caine writes of his late co-star. “Absolutely floored me the first time I saw him in action – I was terrified.”

Ledger’s performance forced the rest of the cast to “raise our game,” Caine adds. Ledger’s turn as the Joker is regarded as one of the greatest villain performances in movie history. He posthumously won the Oscar for best supporting actor. Ledger died in January 2008 at 28 years old, a few months before the July theatrical release of “The Dark Knight.