The adventure begins on Halloween with Skylar (Olivia Holt), a fearless fifteen year-old teenager with a powerful singing voice, prepares for the ultimate Halloween bash with her best friends, Henry and Sadie. The plan for Skylar to sing at the party, after Myra got hurt, with rock band member Ryan Dean. Skylar agreed after finding out Ryan was too nervous to sing it himself. Skylar was crushed when her parents make her stay home and even put on an alarm system to keep her in. She attempts to sneak out of the house by cutting the power so the alarm system won't work. That unfortunately unleashes a monster named Deimata (that was contained in her parents hunting unit) who is determined to feed the fear on Skylar and her family forever. As Skylar’s world is turned upside down, she learns that her parents have been keeping a big secret – that she comes from a long line of monster hunters. She is the 5th generation. Now, it’s up to Skylar and her friends to channel their inner strength and conquer more than just this monster. Every person has their own personal monster, which feeds on their fear.
Now that Deimata is loose, Skylar experiences all the fear she never had before and tries to deny what is happening. She, Sadie and Henry go, armed with Skylar's parents' monster hunting tools, to the party at the McQuarry Mansion. But Henry becomes frozen in fear, after getting scared of his monster. Cobb, her parents assistant, comes and takes him back home to fix him. Meanwhile, Deimata lures Skylar's parents into a trap by pretending that Skylar was in trouble. After this, Myra, Skylar's rival, who is at home with a broken neck is eating ice cream. Soon, the red smoke comes out and it transforms into Deimata. She then controlled Myra and goes to the party where she publicly insults Skylar of being nervous to sing at Ryan's party and Sadie comforts Skylar after she runs out, embarrassed. A possessed Myra sings in Skylar's place and turns to Theodosia and Bob (Sadie and Henry's monsters). Myra falls downstairs after Deimata leaves Myra's body as Skylar and Sadie find her. Myra informs them about Deimata and how she can possess people- like she did with her. Skylar thanks her, and she and Sadie rush to save the people upstairs.
During a confrontation with his personal monster, a fixed and armed Henry learns that letting go of your fears will cause the monsters to disintergrate into nothing. He goes to the mansion to inform Skylar of this. So, she grabs the microphone and tells Ryan to grab his guitar and meet her outside. But, Deimata possesses Ryan to better discourage Skylar from facing her fears, but he manages to break free by facing his greatest fear: asking Skylar out. Skylar faces her fears and sings in front of everybody, while Ryan and his band performs as well. While Skylar sings, all the monsters vanish and Sadie also gathers the courage to stand up to Theodosia by spelling things she couldn't when she was a little girl. When all the monsters are all vanquished, Deimata comes and reveals she cannot be destroyed that way. She then reminds Skylar that she still has Skylar's parents in captivity, and Skylar rushes off to find them, with Sadie and Henry following behind with everybody especially Ryan and Myra watches them from a distance.
Skylar and her friends try to fight off Deimata, but she doesn't seem able to be stopped. Although Skylar has overcome her fear, she soon realizes Deimata is still feeding off of her parents' fears—about Skylar's safety. Once Skylar gets her parents to trust her, Deimata is weakened and the three friends defeat her and capture her. At the end of the movie, Henry and Sadie are shown having no fear by doing what they are scared about doing the most. Later that day, Skylar and Ryan sing at Ryan's party in his basement. Myra becomes friends with Skylar. However, in a post-credits scene, Deimata blows on the glass in the hunting unit, cracking it and we hear it break as Deimata's laugh is heard one last time, hinting at a sequel.
- Olivia Holt as Skylar Lewis, a strong, fearless teenage girl with a powerful singing voice. Learning that her parents are monster hunters, she discovers fear for the first time.
- Brendan Meyer as Henry, one of Skylar's best friends who is not too brave and is routinely bullied by the school jocks.
- Kerris Dorsey as Sadie, Skylar's nervous best friend who dreads public speaking.
- Luke Benward as Ryan Dean, a friend of Skylar who has a crush on her. He is the lead guitarist in his band, called The Backbeats.
- Katherine McNamara as Myra Santelli, Ryan's ex-girlfriend who resents Skylar until she saves her from Deimata.
- Tracy Dawson as Deimata, Skylar's personal monster who previously tormented her grandfather before his death.
- Anna Galvin as Theodosia, Sadie's personal monster, representing her fear of failing in school.
- Stefano Giulianetti as Bob the Scarecrow, Henry's personal monster, representing his dismay of being a coward.
- Jennifer Aspen as Julie Lewis, Skylar's mother and a fourth-generation monster hunter.
- Brian Palermo as Steve Lewis, Skylar's father and a monster hunter.
- Adam Chambers as Cobb, a friend of Skylar and her family and a monster hunter-in-training. He helps Skylar, Henry and Sadie capture the monsters that were released.
- Kurt Ostlund as Lead Jock and Henry's bully.
- "Fearless" - Olivia Holt
- "Had Me @ Hello" (Reprise) Olivia Holt, Luke Benward & Katherine McNamara
- "Nothing's Gonna Stop Me Now" - Olivia Holt
- "Had Me @Hello" - Luke Benward
- "I Got My Scream On" - China Anne McClain
- "Superstar" - Sia Furler
- "Nothing's Gonna Stop Me Now" - Katherine McNamara
It premiered on Friday, October 12, 2012, earning 4.9 million viewers with the number 1 scripted cable TV telecast of the night and 2nd TV Movie of 2012 in Kids 7-11 and Teens. The film had 271,000 viewers in the UK and Ireland when it premiered on October 26, 2012. Unlike Skylar, Ken has a chance to use a monster gun to stop his monster, Traul. he's a bad monster