Help him feel safe and practise settling in his room in small steps. A child can understand that a story is invented and still feel frightened when the lights go out.

I’d leave the physics discussion aside. Asking why the creature collects children may keep his attention on the frightening story; discussing possible future teleportation could also leave him thinking, “So perhaps it could happen.”

Try this approach:

- **Acknowledge the feeling and state the fact simply.** “That story really frightened you. Slender Man is a made-up character. You’re safe here, and I’ll help you settle.” Avoid calling his fear silly. The American Academy of Pediatrics recommends sympathy and cautions against ridicule or pressure to be brave. [AAP guidance](https://www.healthychildren.org/English/health-issues/conditions/emotional-problems/pages/Understanding-Childhood-Fears-and-Anxieties.aspx)
- **Talk during daylight.** Let him explain what worries him, then agree on a bedtime plan together. Keep bedtime itself calm and predictable: a familiar book, a hug, perhaps a night-light, and a few slow breaths. Routines and relaxation can help anxious children. [NHS guidance](https://www.nhs.uk/mental-health/children-and-young-adults/advice-for-parents/anxiety-in-children/)
- **Reduce your presence gradually.** For example, begin by sitting beside his bed, then move your chair farther away over successive nights, then sit at the doorway, then offer brief check-ins. Agree on manageable steps and keep promised check-ins. Praise effort specifically: “You stayed in bed while I was outside for two minutes.” Gradually facing feared situations is an established approach to childhood fears. [AAP guidance](https://www.healthychildren.org/English/health-issues/conditions/emotional-problems/pages/Understanding-Childhood-Fears-and-Anxieties.aspx)
- **Give him a response for school.** Practise: “I don’t want to hear scary stories.” If the other child keeps deliberately frightening him, involve the teacher. Limit further scary videos or searches while he settles.

You can’t prevent every frightening story from reaching him. You can help him learn what to do when fear arrives.

If he keeps crying at bedtime, loses substantial sleep, or starts avoiding school or other activities, speak with his pediatrician or a child psychologist. Persistent fear that disrupts daily life deserves support; you can seek help now if the distress is already substantial. [NHS guidance](https://www.nhs.uk/mental-health/children-and-young-adults/advice-for-parents/anxiety-in-children/)