Nettle walks you home as if she were the keeper and you were the wet dog.

People on the landing see a black shape and start the old sentence. Then they see the wag. Then they see you, holding a rope you borrowed for a collar. The sentence falls apart in the nicest way.

You make a poster. Jonah, if he is anywhere near a marker, has surprisingly good block letters:

BLACK DOG = NETTLE, LOST, FRIENDLY.
Eyes shine (tapetum lucidum). Please return to the landing. Treats yes. Curses no.

Ms. Ellison laminates it because she laminates what matters. Dev staples it under the will-o’-the-wisp warning. Aunt Mara finds Nettle’s real collar behind a sandbag, which is so exactly this marsh that nobody even sighs.

The legend gets a sequel people laugh with. Kids still get a shiver on the dike at midnight—that is allowed—but the shiver has a name and a dog biscuit.

Nettle sleeps on the cottage rug and snores like a tiny saw. The marsh does its night noises. You write: black dog = canid + story + dark. This one likes the couch.

THE END

What you learned: “black dog” folklore grows from real dogs, foxes at dusk, and fear on lonely paths. Eyes shine because of a mirror in the eye, not cursed lanterns. Sometimes the ghost wants a collar and a ride home.