Robert Bridgestone (Kerwin Mathews), a divorced father, takes his son Richie (Scott Sealey) to the family mountain cabin. During a moonlight hike, the two are attacked in the darkness by a werewolf. During the struggle, the werewolf falls into a ravine and is impaled on a wooden fence, but not before biting Robert. Upon investigation, they find their attacker to be human. Unable to identify the body, the local sheriff concludes their attacker was a crazy drifter. Richie insists it was a werewolf but his father and the sheriff laugh it off as childish imagination.
Concerned with Richie's story, Sandy (Elaine Devry) insists her ex-husband talk with her son's psychiatrist. The psychiatrist (George Gaynes) says that Richie's werewolf fixation stems from his inability to accept that his father killed a man, and instead has concocted a fantasy wherein his father bravely battles a monster. He suggests Robert take his son back to the cabin, predicting that when Richie returns to the scene and sees that everything is normal, his interest in werewolves will cease.
Returning to the cabin during another full moon, Robert experiences a wave of pain and sends Richie off to the stream. As he watches in a mirror, Robert changes into a duplicate of the creature he'd killed. When Richie sees what is apparently the same werewolf resurrected, he flees to the woods, crossing a mountain road. The werewolf pursues, causing vehicles to crash. One driver is then dismembered by the creature. Richie comes upon two newlyweds camping. While they don't believe the boy's story, they see his distress and agree to take him home. Arriving at the cabin, Richie's father is nowhere to be seen, and Richie begs the man to let him return with him to the camper for the night. The next morning Robert, appearing dazed and confused, shows up at the camper, and tells the couple he's been searching for Richie all night. Richie tells his father about the werewolf, but Robert is clearly losing patience with his son's fantasies.
During the following night's full moon, Robert transforms, and searches through the house for Richie who, in anticipation, has hidden himself. The werewolf then seeks out the newlyweds, pushing their camper down a hill. He mutilates their bodies, carrying away one of the heads. Returning to the cabin's shed just before daybreak, he digs a hole to bury the head. Richie, hearing noises, sneaks down to the shed and witnesses the werewolf's changing back into his father. Moments later, the sheriff arrives to report on the previous killings, convinced of a connection between the attacks. On the drive home, Richie questions his father about his actions, but Robert dismisses everything, clearly irritable and bothered about his memory blackout. Richie jumps hurriedly out of the car upon arriving at his mother's, telling her that he's scared to be alone with his father, because his father is a monster.
It is agreed that another visit with the psychiatrist is in order. The doctor tells Robert that Richie genuinely believes Robert is a werewolf, and that these type of fantasies can be quite powerful for children. It is suggested that this time a family weekend should be planned which includes Richie's mother. As the session goes on, the full moon rises.
The next day, a reluctant Richie and his mom prepare to leave for the cabin with Robert, unaware that the headline of the morning paper reads "Local Psychiatrist Murdered". The three set out for the cabin, stopping at a hippie commune on the way. The hippies, with their wild-eyed leader (Bob Homel), are forming a circle of power to drive away evil spirits. When the family stop to watch, the hippies shout at them to join in, and while an amused Sandy agrees, when Robert tries to enter the circle, he is stopped short and cannot move further, as if an invisible barrier were before him. A disturbed Sandy grabs him and they get back in the car and continue to the cabin, where they settle down for the evening. Sandy talks gently with Robert, confessing that she's really missed him, and that perhaps they should get back together. The full moon rises, and Robert turns his back on her, silently walking away. In the shed he finds Richie, digging up the bag he'd seen his father (in werewolf form) burying on their previous visit. Robert grabs Richie, clearly in the first stages of transformation, and begs Richie to lock him in the shed. Richie does so, but as he finishes, his mother sees him, and hears the noises in the shed. Richie tells her it's his dad in there, whereupon she scolds Richie and tries to open the shed. Richie screams at her just as a clawed hand bursts through the door. Richie and his mother run to the car, escaping just as the werewolf emerges, screaming and snarling.
In town they seek help from the Sheriff, but upon returning to the cabin find the creature gone. The Sheriff leaves some men to stand guard. Later that evening, as Sandy sleeps by the fire, the werewolf slips silently through a cabin window. Sandy awakes to find it staring her in the face. It starts to carry her off, but on hearing her screams, the deputies burst in, opening fire as the monster jumps out the window. Richie begs for them not to hurt his dad, but of course everyone still cannot accept that it is a werewolf, let alone Richie's father.
The werewolf attacks the hippie commune and as the sun rises, the werewolf weakens and collapses. The hippies witness the beast's transformation, and though not understanding what they'e seeing, they pray for the creature's soul. That evening, as the sheriff organizes a search party, Richie breaks away and heads off to try to save his father. As the moon rises, Richie finds his father, once again transformed, who grabs him and carries him off, with the mob close behind. Cornered, the werewolf attacks Richie, biting him on the arm, before a hail of gunfire distracts him. The bullets cannot kill him, but frantically attempting to flee, he stumbles and falls on the broken stake that held the hippies' cross to the ground. It pierces his heart, and as a horrified Richie and Sandy watch, the werewolf transforms back into Robert. The last thing we see is Sandy examining her son's bite mark, with dawning horror on her face (implying Richie will be cursed as a werewolf now).Kerwin Mathews as Robert Bridgestone
Elaine Devry as Sandy Bridgestone
Scott Sealey as Richie Bridgestone
Robert J. Wilke as The Sheriff
Susan Foster as Jenny
Jack Lucas as Harry
Bob Homel as Brother Christopher
George Gaynes as Dr. Marderosian
Loretta Temple as Monica
David S. Cass Sr. as Deputy (as Dave Cass)
Harold Goodwin as Mr. Duncan
Tim Haldeman as First Guard
John Logan as Second Guard
Eric Gordon as Hippy 'Jesus Freak'
Paul Baxley as First Werewolf
The New York Times wrote, "Skip "The Boy Who Cried Werewolf," the standard, slapdash half of a new horror double bill that includes something called "Sssssss" (as in snake). There is some amusing business in "Werewolf" toward the end, as the thrashing werewolf (Kerwin Mathews) tangles with a bunch of Jesus Freaks. Bob Homel, who plays the leader, also wrote the picture."