A short story with a twist, that happens in the Grisha-verse, but doesn't have any connection with the actual story of the Grisha trilogy. Or so I thought. 
 Most of the time I ignore short stories and so I skipped this one after reading Shadow and Bone last summer. But not long ago I saw friends discussing this novella and mentioning that, while all the novellas (except the Tailor) are just separate fairy-tales, they also, in a way, feature guys from the Grisha Trilogy. 
 The Witch of Duva features the Darkling, and the Too-Clever Fox has to do with Sturmhond/(view spoiler)[Nikolai (hide spoiler)]. Leigh Bargugo used this subtle way to let us see and understand her characters better, and you just can't help but make the connection. 
 The Witch of Duva makes you think about villains and villainy and question your judgement about those notions. It shows how one person's perspective seriously limits their understanding of certain things and how you sometimes have to think outside the box to see the real villain. 
 I'm not saying anything more because I want to keep this review spoiler-free. If you haven't read this story, do it. Hopefully it will make you see the Darkling in a new light.