The Sins of the Sorcery Summit (titled Heksenaanval in the original Dutch) is a comic story written by Jan Kruse, penciled by Sander Gulien and inked by Tony Fernández. It features Scrooge McDuck, Donald Duck, Huey, Dewey and Louie Duck, Magica De Spell, Ratface, Witch Hazel, Madam Mim and Gladstone Gander. Witch Winifred is also mentioned.
As one more plan to steal Uncle Scrooge's Number One Dime, Ratface suggests that sorceress Magica De Spell enlist the help of more experienced "true witches". They come in the form of Madam Mim and Witch Hazel, who kidnap Scrooge and steal him away to the reportedly-haunted Fort Lockman, threatening to blow it up in an explosion of transformative magic that would turn it into a giant fox terrier and Scrooge into a flea — unless Scrooge gives up the location of the Dime's new hideout. Meanwhile, Donald Duck and Gladstone Gander bet over spending the night in "haunted Fort Lockman" and end up the grain of sand in the cogs of the witches' scheme.
This story was first printed on the 24th of October, 2014 in the Dutch Donald Duck #2014-44. It was printed in English in Uncle Scrooge #435, with the script slightly altered (by Jonathan Gray), as usual with modern American translations.
In that printing, references to the difference between sorceress Magica and true witches Hazel and Mim were emphasized, and the abandoned fort was dubbed Fort Lockman in homage to vintage Disney writer Vic Lockman. The name of "Tanneke" (here fairly obviously referring to the Grimhilde of The Golden Christmas Tree rather than Mammy Bammy, due to the focus on Christmas) was once again rendered as "Winifred", as it had been in the localization of the Dutch sequel to The Golden Christmas Tree as Winifred's Revenge.