Shadow of the Vampire, the first film produced by Nicolas Cage, is a shockingly funny spellbinder with a plum part that Cage — talk about shocks — handed to Willem Dafoe instead of himself. Dafoe, who has never been better, bites into this Oscar-bait role with an uncanny knack for blending mirth and menace. Here are the facts: In 1921, German director F.W. Murnau cast unknown actor Max Schreck to portray the undead Count Orlock in what would become the silent-film classic Nosferatu. As screenwriter Steven Katz wickedly sees it, Murnau, played to the creepy max by John Malkovich, knew that Schreck (Dafoe) was a real vampire when he hired him, promising him the neck of leading lady Greta Schroeder (Catherine McCormack) at the end of shooting if Schreck helped Murnau achieve cinematic immortality. It’s a deal that most directors today would make in a snap if they could. That’s the premise, and an exceptional cast, including Eddie Izzard as a hambone actor, gleefully plays variations on it. But Dafoe goes deeper. With the help of director E. Elias Merhige (Begotten), who evokes the silent-film era with visionary brilliance, Dafoe captures the humanity in the monster. It’s a mesmerizing spectacle.