Five Nights At Freddy's: Security Breach - Wikipedia

Five Nights at Freddy's: Security Breach takes place in a massive entertainment complex known as Freddy Fazbear's Mega Pizzaplex, which has animatronic mascots, Glamrock Freddy, Glamrock Chica, Montgomery "Monty" Gator, and Roxanne "Roxy" Wolf. As the animatronics perform for an audience at the complex, Freddy suddenly suffers a malfunction and breaks down on stage, ending the performance. Afterwards, he is taken to Rockstar Row and discovers that a young boy named Gregory is hiding inside his stomach compartment. After the discovery, Vanessa, a female security guard and the only human on staff for the night, orders all animatronics and staff bots. The animatronic mascots have become aggressive for known reasons—to search for Gregory.

As a result of the malfunction and his fear of Vanessa, Freddy disobeys her orders and instead guides Gregory to the lobby to help him escape, only for the complex to lock up for the night and trap him inside until they reopen in the morning. Until the complex reopens, Freddy helps Gregory survive the night and guides him through the Pizzaplex. After the two elude Vanessa and the animatronics and take refuge in a security office, Gregory manages to gain access to the complex's surveillance system. To obtain access to certain parts of the complex, Gregory attempts to acquire high-level security badges from the complex's daycare, encountering the Daycare Attendant in his "Sun form". Whilst in the daycare, a power outage forces Gregory to confront Sun's hostile alter ego, Moon. He manages to restore its power, but the Attendant (as Sun) kicks Gregory out for turning the lights off. It proceeds to then alert the animatronics of his location before he is rescued by Freddy.

Shortly afterwards, Gregory is captured by Vanessa and is later confined in a party room. Vanny—a woman in a white patchwork rabbit costume—approaches him, but he escapes and reunites with Freddy. The two venture into the basement, where Moon ambushes them and captures Freddy. Gregory proceeds throughout the basement and avoids the animatronic endoskeletons, before finding Freddy being interrogated by Vanessa, accusing him of colluding with Gregory. Gregory repairs Freddy after Vanessa leaves, (Also giving him a battery upgrade in the process.) and begins dismantling the other animatronics to use their parts to upgrade Freddy.

Shortly after the upgrades are completed, 6:00 a.m. arrives and the complex's doors open, but Vanessa requests that Gregory to meet her for a "reward", which is several different recordings of Vanessa and an unknown person undergoing therapy. Gregory is then left with the choice of leaving the complex, staying to continue exploring the complex's secrets and trying to solve the remaining mysteries, or confronting Vanny, who was also responsible for several missing children cases within the complex.

The game has six different endings, each of which depends on Gregory's actions throughout the game and how he exits the complex. One ending in particular–known as the "Burntrap" ending–results in a boss fight against an animatronic known as Burntrap before it is ultimately defeated by Gregory. It also reveals the remnants of a past Freddy Fazbear's Pizza location that was buried beneath the complex years ago. Another ending–known as the "Princess Quest" ending–results in Gregory learning that Vanessa and Vanny are the same person. After a final confrontation in Fazer Blast, Gregory manages to save Vanessa, and together with her and Freddy, leave the complex as the sun begins to come up.

Ruin

Some time after the events of the main story, Gregory becomes trapped within the Pizzaplex–now abandoned–once again, this time by an unknown entity beneath. To free him, his friend Cassie arrives and collects different items around the complex. These items include a security mask, which allows her to access a Virtual Augmented Neural Network Integration ("V.A.N.N.I.") unit. Gregory guides Cassie through the Pizzaplex and instructs her to disable several security nodes in order to access a sinkhole, with the last one being a now-blinded Roxanne "Roxy" Wolf which Cassie tearfully disables. As she goes through the complex, Cassie encounters damaged versions of the complex's animatronics, in which she fries Monty to death, repairs Chica using her voicebox, and fuses the Attendant's Sun and Moon forms into an "Eclipse". She is also hunted by a digital entity in the form of a rabbit whenever she is wearing the security mask.

After disabling Roxy, a distressed Cassie makes her way into the sinkhole and the remnants of Freddy Fazbear's Pizza. She disables the security protocols of the location, and shuts down a program named M.X.E.S. (the server for the rabbit entity). When she enters the room Gregory was trapped in, she instead discovers a skeletal animatronic known as the "Mimic", who is using Gregory's vocal patterns to trick Cassie into releasing him. The Mimic chases after Cassie as the real Gregory leads her to an elevator, with the Mimic overpowering a rebooted Roxy in the process.

As the elevator ascends, Gregory reveals that the Mimic was trapped in the sinkhole for some time, and M.X.E.S. was built to stop it from escaping. Since Cassie shut down the security nodes and M.X.E.S., the Mimic is now free. Though Gregory appreciates Cassie risking her life for him, he tells her that he cannot allow the Mimic to be freed. Gregory apologetically disables the elevator, sending the car plummeting to the ground with Cassie still inside, where she is found by Roxy. An alternate ending can also be acquired where the Mimic is defeated by Cassie via a device that grabs it and shuts it down.