The Tailor is a fantastic short story, by Leigh Bardugo. It is a story told from Genya's point of view, the only Grisha with her particular abilities (as far as we know) and a maybe friend of Alina, the main character in Bardugo's Grisha series. In about 16 pages, Genya breaks your heart. Alina is possibly her only friend, but Genya has endured so much, living in the palace with a vengeful Queen and a lecherous King, that she makes a decision that she believes will result in her freedom. I appreciate that Bardugo doesn't soften things in the palace, she gives Genya very believable, though horrible reasons for doing what she did.
I've read Bardugo's other Grisha related short stories, but The Witch of Duva and The Too-Clever Fox were both "folk tales". The Tailor is the first Grisha short story I have read that is from the perspective of one of the other characters. I really enjoyed the folk tales. Those stories are what motivated me to read the Grisha series. The Tailor, however, sheds light on a character's motivations that are hinted at in the first novel, but don't get fully explored. I also appreciate that this story is available for free, something that couldn't fit in the first novel, but fans of Bardugo's would want to read. The Tailor is the perfect set up for Siege and Storm, not that it hints at anything or even feels like a set up, but it made me energized to read the second Grisha novel and more by Bardugo.