Shiloh Arielle Nelson is 17 years old. She has light skin, long brown hair and green eyes. She usually wears her M.O.M. Agency outfit: a purple sleeveless top, green utility pants with several pockets, black straps and buckles, a small purple bandana around her right arm and purple boots. She is the youngest Nelson sibling and the leader of the M.O.M. Agency. Shiloh is intelligent, determined, caring, brave and naturally takes charge when everyone else is panicking. She is also impatient and can be reckless because she is willing to put herself in danger to protect the people she cares about. She has a particularly strong bond with her older brother Elijah. In the Backrooms, Shiloh is focused on getting everyone out safely. She is suspicious of Liam and doesn't easily accept his attempts to get closer to the group. Liam's mysterious behavior creates a constant friend-or-enemy tension between them.

Elijah John Nelson is 27 years old. He has light skin, dark hair and brown eyes. His usual M.O.M. Agency outfit consists of a blue shirt underneath a red-and-black checkered flannel, dark blue pants and gray boots. Blue is his signature color. Elijah is Shiloh's older brother and one of the group's main leaders. He is intelligent, strategic, protective, loyal and usually tries to think of a practical solution when everyone else is panicking. However, he can become easily frightened or frustrated when situations become overwhelming. He can also be confident and occasionally overly proud. Elijah is extremely protective of Shiloh and watches Liam closely because he doesn't completely trust him. Even when Elijah is scared, he tries to keep the group moving and protect his family. His strongest relationship in this story is his sibling bond with Shiloh.

Jocelyn is 8 years old. She has light skin, blond-brown hair and green eyes. She is the youngest member of the group and is Shiloh's niece and Elijah's niece. In the Shiloh & Bros universe, she is associated with the M.O.M. Agency and is often portrayed as a Mini Crewmate. Jocelyn is energetic, witty, dramatic, stubborn, impulsive, competitive and extremely unpredictable. She can be easily distracted and tends to react to dangerous situations in ways nobody expects. Her chaotic sense of humor often contrasts with everyone else's seriousness. In the Backrooms, Jocelyn is the group's wildcard. While Shiloh and Elijah are focused on escaping and Liam remains mysterious, Jocelyn can suddenly do something completely unexpected. She is not romantically involved with anyone; her relationships in this story are purely family and team relationships. She is especially connected to Shiloh and Elijah as their niece.

Liam is 18 years old in this story. He has light skin, brown hair and a lean, athletic appearance. His usual outfit consists of a gray sleeveless shirt, a red scarf, black fingerless gloves and gray pants. He has a confident, capable presence and moves like someone who is used to dangerous situations. Liam is mysterious, skilled, unpredictable and difficult for the others to read. He often remains calm when everyone else is panicking, but he deliberately pushes Shiloh's patience and creates doubt about what he actually wants. He has a complicated history with Shiloh and keeps trying to prove that he can be useful to her and the M.O.M. Agency. Shiloh remains cautious around him, while Elijah is openly protective of Shiloh and suspicious of Liam. This creates a constant tension between Liam and the siblings. Liam can seem like either an ally or a potential problem, which makes it difficult for the group to know exactly where he stands. His story role includes an apparent interest in Shiloh, in easier words. Liam has a crush on Shiloh / he likes Shiloh.