Wise Man, played by Ian Abercrombie, is a character in the film Army of Darkness.
According to the Wise Man, the only way that Ash can return to his time is through the magical Necronomicon Ex-Mortis. Ash then starts his search for the Necronomicon. As he enters a haunted forest, an unseen force pursues Ash into a windmill, and he crashes into a mirror. Small reflections of Ash in the mirror shards come to life, with one becoming a life-sized clone, after which Ash kills and buries it.
When he arrives at the Necronomicon's location, he finds three books instead of one, and has to determine which one is real. Realizing at the last moment that he has forgotten the last word of the phrase that will allow him to remove the book safely – "Klaatu barada nikto" – he tries to mumble and cough his way through the pronunciation. He grabs the book and begins rushing back. Meanwhile, unknown to Ash, his ruse has failed and the Deadite captain resurrects in his clones' body, uniting other Deadites into the Army of Darkness.
In the alternate ending, the Wise Man tells Ash to swallow 6 drops of the potion to return to the present, unfortunately, due to a distraction by falling rocks, Ash miscalculates the amount of potion needed to be able to correctly return to his own time, swallowing 7 instead of 6. As a result, he wakes up in a post-apocalyptic future where human civilization is destroyed, and he screams in dismay at having overslept.