Director Sam Raimi was originally attached to the project before dropping out to direct Darkman instead. Heavily marketed as director Friedkin's first foray into the horror genre since 1973's The Exorcist, the film had a troubled production, with the script undergoing numerous changes that continued well into the shooting process.
The film was released in the spring of 1990, and was met with generally unfavorable critical reception, later making Roger Ebert's "most hated films" list. A cable television version of the film was credited to "Alan Von Smithee", indicating that Friedkin wished to disassociate himself from its release. Although a critical and commercial failure, the film later found an audience as a cult film.
The opening cards explain that ancient druids worshiped trees, sometimes offering them human sacrifices. Some of these trees were connected with evil.
At the Sheridan home, Molly and Allan Sheridan head off on a trip, leaving their two children in the care of their nanny, Diana Julian. Once alone and with the children sleeping, Diana kidnaps the daughter. Molly realizes she has left her glasses at the house, and upon returning she sees that her daughter is missing. Diana, out in the forest, approaches a giant, old gnarled tree, and holds up the baby, which then disappears from her hands. The roots of the tree show the baby's face, as it has been sacrificed to keep the tree alive. As Diana sits on the ground near a pool of water, her reflection disappears, leaving that of a growling wolf.
Three months later, Phil and Kate Sterling move to Los Angeles, where Phil has gotten a job with an advertising agency. Kate reveals to Phil that she is pregnant; she gives birth to a baby boy, Jake. They decide to hire a nanny so that both parents can continue to work. They interview a number of candidates recommended by the Guardian Angel agency. Two seem most suitable: a young woman named Arlene Russell, and a caring British woman named Camilla Grandier.
After Arlene dies in a bicycling accident, Camilla is hired and quickly becomes an invaluable member of the household. However, one night, Phil has a nightmare where he sees a wolf attacking Jake. Later in the day, Camilla and Jake are outside in a field when she's confronted by three gang members, who chase her and Jake into the woods. After knocking her to the ground, one of the men stabs her and attempts to rape her at the base of the old tree. The tree comes alive and uses its branches to eviscerate the three men, consuming one of them. Camilla sits on a branch above the ground, cradling the baby, while wolves devour one of the men. A giant spike impales the last man, before he is engulfed in flames.
Kate and Phil throw a dinner party, attended by Ned, their neighbor and the architect of the house, and Phil's bosses from work. During dinner, the conversation turns to Camilla and her value to the household. Later in the evening, Ned, who has taken a liking to Camilla, invites her to his house; she politely declines. Phil dreams of having sex with Kate, who suddenly turns into Camilla.
The following night, Kate helps Camilla get dressed up for some window shopping in town. After she leaves, Ned arrives with a bouquet of flowers for Camilla. Kate encourages him to go after Camilla; Ned hops into his truck and catches sight of Camilla heading into the forest. Ned follows on foot, and eventually finds her bathing in the creek. Suddenly she vanishes, reappearing on the giant tree. As she lies naked on a branch, she begins to fuse with the tree bark. Ned is discovered by the pack of wolves, and flees back to his house. While trying to call the police, his phone cuts out. After locking all the doors, he calls Phil and Kate, and leaves a rambling message about what he saw in the forest. The wolves break into the house; Ned runs into the living room and sees Camilla, naked and ashen, on the hearth, warning him that he shouldn't have followed her. The wolves rush in and kill him. Camilla drags Ned's body away, and all traces of his death mysteriously vanish.
Phil wakes up in the night and sees the answering machine beeping. The first message is from a stranger, Molly Sheridan. After leaving her phone number, she says that it is urgent she and Phil speak. The next message is from Ned. As Phil listens to Ned's message, Camilla enters and tells Phil he needs to look at Jake, who appears ill. The following day, Phil goes to the Sheridan house, meeting Molly and her son Scotty. Molly describes the disappearance of her baby daughter. Their former nanny, Diana, disappeared at around the same time. The police have been unable to find any evidence that Diana even exists. She begs Phil to arrange for her to see Camilla, suspecting she is really Diana. Returning home, Phil searches the house for Camilla. Finding no one, he listens again to the message Ned left, warning Phil and Kate not to let Camilla back into their house. Phil rushes over to Ned's house, and finds the door wide open, but no one inside. Phil arrives home where Camilla is with Kate and the baby, and confronts her, telling her to leave his house, during which the baby becomes violently ill; they take him to the hospital, where he displays coma-like symptoms.
At the hospital, Jake awakens, and Phil rushes off to find the doctor. Camilla suddenly appears in the hospital room. She tries to leave with the baby, when Phil blocks her path. He grabs Jake and knocks Camilla to the ground. The Sterlings leave the hospital and head home, to find a wolf standing guard inside. As they slam the door on it, more wolves surround them. Kate runs to their Jeep, and Phil flees into the woods with Jake, where he is chased by Camilla, who levitates through the air. Kate drives into the forest, where she finds Phil being confronted by Camilla; she hits Camilla with the Jeep, killing her. As Phil examines Camilla's body, he sees faces of babies embossed in the tree bark.
After a detective tells them that he could find no evidence Camilla ever existed, Kate and Phil decide to leave the house. Phil enters the woods with a chainsaw to cut down the tree; meanwhile, Kate is attacked by Camilla at the house, who appears as part-tree and part-human. When Phil attempts to cut the tree, he is entangled in its branches, which bleed when he saws through them. As Phil attacks the tree, patches of skin start to fall off of Camilla. Camilla drags Kate down the stairs and throws her into the living room. As Camilla approaches Jake, Phil chops off a large branch from the tree, causing Camilla's entire leg to sever from her body. Kate then pushes Camilla out the window. As she falls towards the ground, the tree begins to fall and explodes before landing; Camilla then disintegrates before touching the ground. Phil arrives back at the house, and finds Kate holding Jake.Jenny Seagrove as Camilla Grandier/Diana Julian
Dwier Brown as Phil Sterling
Carey Lowell as Kate Sterling
Brad Hall as Ned Runcie
Miguel Ferrer as Ralph Hess
Natalia Nogulich as Molly Sheridan
Pamela Brull as Gail Krasno
Gary Swanson as Allan Sheridan
Jack David Walker as Punk #1
Willy Parsons as Punk #2
Frank Noon as Punk #3
Theresa Randle as Arlene Russell
Xander Berkeley as Detective
Ray Reinhardt as Dr. Klein
Jacob Gelman as Scotty Sheridan
The Guardian was shot on location in Los Angeles and Santa Clarita, California. The forest location featured in the film was shot in a nature preserve in Valencia, California, near Six Flags Magic Mountain.
The original script for The Guardian bore a closer resemblance to its source material, The Nanny by novelist Dan Greenburg, which told the story of a nanny who steals children. According to screenwriter Stephen Volk, Sam Raimi was originally attached to the picture. Raimi dropped out of the production to direct Darkman, at which point William Friedkin was brought in to direct. The script, which had originally been conceived as a tongue-in-cheek thriller for Raimi, eventually "metamorphosed into something different" during the course of filming, as Friedkin made numerous changes. Volk attempted to rework the script for Friedkin, initially re-writing the character of the nanny as a real-life Lilith, the child-stealing demon from Jewish mythology. Friedkin dismissed the idea, and Volk then reworked the script into a straightforward psychological thriller about an unhinged woman stealing children; however, Universal Pictures objected to the reworking, stating that they wanted a "supernatural" horror film given Friedkin's reputation for The Exorcist (1973). Amidst the shifting script, Friedkin began auditioning for the role of Camilla (Uma Thurman was originally a candidate for the role prior to the script changes). After Volk suggested using elements from the M.R. James story "The Ash-tree" in the script, Friedkin became fixated on incorporating a tree into Camilla's backstory. Volk reportedly suffered a nervous breakdown and left the production, leaving Friedkin to finish the script's loose ends after filming had already begun.
In a 2015 interview, Jenny Seagrove recalled visiting Friedkin at his home in Los Angeles, where he told her he'd been reading on Druid mythology and wanted to incorporate it into the film. According to Seagrove: "Pages were flying at us [...] and then suddenly this idea of this weird kind of tree came about, and suddenly my character was not just a nanny but she was a Druid character who turned into a part of the tree, and she had to feed the tree—things were evolving all the time."
Seagrove underwent numerous extensive makeup transformations in the film, at times covered in tree bark during the metamorphosing scenes. The tree featured in the film was constructed by the special effects department in Burbank, California, and transported to the nature preserve in Valencia. The tree contained tubes of circulating fake blood in order for the tree to properly "bleed" when cut.
The TV version of the film ends with Phil and Kate returning home from the hospital with Jake, while Camilla is alive and naked at the tree. Director William Friedkin disapproved of the television cut of the film and removed his name from the credits, naming "Alan von Smithee" as the director.
The video and DVD versions have the full ending, in which Camilla appears in her true form and tries to take the baby from Kate, but Phil cuts down the tree with a chainsaw, thus killing both it and Camilla.
The Guardian was released in North American cinemas on April 27, 1990, opening at #3 at the box office on 1,684 screens. It grossed USD$5,565,620 its opening weekend, and went on to gross a total of $17,037,887 domestically.
The Guardian earned mostly negative reviews from critics, and holds a 13% rating on review aggregator Rotten Tomatoes. Roger Ebert of the Chicago Sun-Times gave the film one star out of four and later named it as one of his "Most Hated Films". Janet Maslin of The New York Times gave the film a middling review, saying "[Friedkin] never sustains the story's tension for very long, and even cuts off the scarier episodes before they have a chance to sink in. What's more, he never offers a consistent idea of what sort of evil is at work here." The Washington Post also gave the film a negative review, stating: "the plot is so preposterous that The Guardian never comes close to grabbing attention, empathy or sympathy." Time Out said in their review of the film: "Friedkin opts for up-front hokum, interspersed with impressively ridiculous special effects, including man-eating trees, flying nannies and coniferous chainsaw carnage. A severely flawed but not unamusing venture from a director who should know better."
Actress Jenny Seagrove said of the film in retrospect: "I don't want to put off anyone from watching it because it is good fun," but noted during the first screening that "there was a feeling in the room that it wasn't the sort of picture everyone had hoped it was going to be."
The Guardian was released on VHS by MCA Universal home video on October 17, 1990. It was later licensed by Universal for a DVD release through Anchor Bay Entertainment, which was released October 12, 1999. The DVD features an audio commentary by director Friedkin, as well as the original theatrical trailer. This release has been long out of print and is difficult to obtain.
The film was released on Blu-ray for the first time by Shout Factory on January 19, 2016.