Your magic's never very direct, is it?
The Witch of Dunbroch is an old woman who lives in a cottage in the woods of DunBroch, granting magic to those who seek it. She grants King Fergus with an enchanted helm to help him win a battle against southern invaders, but when things take a turn for the worse, it's Merida who's forced to pay the price of magic...
After the Curse
The Witch grants King Fergus with magic. ("The Bear King")
War has broken out between DunBroch and southern invaders, and fearing he will lose the battle, King Fergus travels to the Witch's cottage. Despite her claims of being a mere woodcarver, he spits out his knowledge of her once turning his wife and sons into bears, and so the Witch admits she may "dabble" with magic. The King is not there for revenge though, but magic himself; he requests something that will allow him to defeat the southern invaders and ensure the fate of DunBroch. Not needing any payment at the moment, the Witch has Fergus sign a contract instead, deeming it an "I.O.U", and from there she gets to work, presenting the King with an enchanted helm. She reveals it has the power to cause any army to following the wearer of the helm, willingly, into battle, no matter the dangers. Fergus ends up taking the helm, but before heading into battle he backs out, not wanting to use magic to force his men after all. He ends up throwing the helm into a river and he and his men fight willingly... up until the King's untimely death. ("The Bear King")
Before the Third Curse
Merida has passed the Witch's test. ("The Bear King")
With two years having passed, Merida is about to be crowned Queen of DunBroch, only for her coronation to be crashed by the Witch, who has finally come to collect payment for the enchanted helm she gave King Fergus. When a price is named though, Merida points out the United Clans are unable to pay what the Witch is asking for, and so she agrees to leave them all be if Merida is able to get her back the helm by the next sunset. However, if the Queen is unable to come up with the money owed, or the helm, the Witch will punish them all by turning all Merida's subjects into bears. As Merida quests to find the helm, King Arthur and Zelena make their way to the Witch's cottage in search of the helm as well, and when almost being drowned in her cauldron by Zelena, the Witch is forced to reveal who she sent to retrieve the helm. As it turns out, the Witch had also been keeping Red Riding Hood trapped in her wolf form, and kept as a guard dog, but with the help of Mulan, the girl is restored to her human form and is able to get away. The Witch later returns to Merida to see if the Queen has succeeded, which she has, but the girl refuses to return the helm. She wishes to destroy it instead, and promises to find another way to stop the Witch's curse. The Witch is proud though, for this was all a test - exactly what Fergus had requested years prior. As a coronation gift, the Witch gives Merida magic ale, allowing her to contact her father in the Underworld. ("The Bear King")