The film stars Clint Howard as an outcast cadet named Stanley Coopersmith, who frequently gets tormented by his mates and advisers at a military academy.

Upon finding a book of Black Mass that belonged to the evil medieval Father Lorenzo Esteban, he taps through a computer to conjure Satan and summons spells and demons to get revenge upon his harassers.

16th-century Spanish Satanist Father Lorenzo Esteban and his followers are told by a priest that they are banished to America and denied God's grace unless they renounce Satan and their evil ways.

While cleaning the church cellar as punishment, he finds a room belonging to Esteban containing books of black magic.

Arriving too late for dinner, he befriends the school's cook, who makes him food and shows him some puppies that his dog just littered.

At home, Miss Friedemeyer again attempts to look over the jeweled pentagram from Esteban's book and is savaged to death by a pack of large black boars.

The film's ending shows Stanley's true fate as his face appears on the computer screen in the cellar with the words "I will return".

The film was shot in three weeks, using locations in Santa Barbara at what is now Garden Street Academy and a condemned church in South Central Los Angeles.

[1] According to DVD commentary, the dilapidated church was superficially renovated for the movie shoot, confusing a priest who previously worked there and causing him to get on his knees and pray to God.

The film was reclassified and re-released in 1987 but with over three minutes of cuts, which included the removal of most of the gore from the climax and all text images of the Black Mass on the computer screen.

[citation needed] In a July 2017 interview for Gilbert Gottfried's Amazing Colossal Podcast, Howard also revealed that the film's producers made him pay for his own toupée.

AllMovie called it "essentially a gender-bent rip-off of Carrie", though "there is enough in the way of spooky atmosphere and well-staged shocks to keep less discriminating horror fans interested.

"[4] PopMatters gave the film a 7/10 grade, despite writing "What started as a standard wish fulfillment/revenge scheme mixed with Satanism flounders with a lack of focus.

"[6] A slightly more favourable review came from TV Guide, who wrote "The directorial debut of Eric Weston, Evilspeak is remarkably engaging, imaginative and well-crafted.