This will result in a game over, where the player can either restart from the last saved game or quit to the main menu.
If Vanny, Vanessa, or any animatronic catches Gregory, they will scream in Gregory's face before they (presumably) either kill or capture the boy. Rather than attacking the player in a certain area where the player always stays, they roam Freddy Fazbear's Mega Pizzaplex looking for Gregory (the player), while the player is required to move around and/or hide.