Runehead Whistle

Runehead whistles are incredibly rare magical items, capable of communicating with runehead wolves. Some would say "summon" them, but this is inaccurate. The whistles are highly prized as a means of protection from deathhowl wolves, as deathhowls are deathly afraid of runeheads. The magic of a runehead wolf is very much a mystery, but deathhowls appear to be vulnerable to it and will flee from a runehead, abandoning their prey.
Because of the magic laws, travel in Hjemtir is rare, and dangerous even for Freewalkers; deathhowl wolves are only one of those dangers, but they are one of the most feared. While owning or even using a runehead whistle is not a guarantee of safety, any of the few who travel in Hjemtir would give their limbs for one of them.
When someone uses the whistle, it sounds to humans like a single note, but to a runehead wolf it conveys the intention of the user. They can tell whether the person using it is in need of help, is seeking a companion, is looking for guidance, and so on, or less pure motives. It is on this basis whether or not they will approach the user.

Context

Runehead Wolves

Magical species sacred to the Enki people, long been associated with wisdom and guidance. It does not attack unless threatened. Large and white with glowing blue runes on its forehead.

Deathhowl Wolf

The saying is if you're close enough to hear a deathhowl, you're as good as dead. Twice as large as a horse, moves fast enough to be a blur, and has impenetrable skin. Its preferred prey is human.

Hjemtir's Magic Laws

Due to a curse on the land, the people of the realm of Hjemtir are unable to travel off their ancestral lands except under specific conditions without becoming Sentenced--magically marked which brings any of a variety of deadly magical consequences.

Freewalker

People exempt from the magic laws due to being born on a certain day of the year.