Years ago Mike thought his little brother Garrett was kidnapped and started to think he was killed and now his parents are dead and he has to take care of his little Abby

He was working at this place as a night security guard at Freddy fazbear's Pizza...he was walking around making sure the animatronics weren't moving or anything

After The spring-trap showdown and he found out Garrett is in fact alive just being more disfigured from the incident and being 18 years old now

One night Mike came home and he glances over seeing Garrett sleeping on the couch with Abby asleep on top of him