Juliet Marillier has been one of my go-to favorites for epic fantasy for years, but this is my first experience with her YA marketed writing. Unsurprisingly, Shadowfell is just as strong as her adult fantasy titles; setting a high bar for other YA fantasy titles. There are only a small number of YA fantasy titles that I've been truly impressed by, often causing me to wonder if perhaps the YA genre isn't built to sustain the type of world building and epic scope that I've come to prefer after years of reading adult fantasy. Shadowfell completely proves this hypothesis false, while simultaneously making it very likely that I'll be even pickier and judgmental about future YA fantasy I choose to read. I haven't decided yet if this consequence is positive or negative...Shadowfell centers around Neryn, who has lost her entire family and her home under the reign of the dark, violent King Keldec. Like her grandmother before her, Neryn is gifted with a canny skill, or magical ability, which is outlawed any where but in King Keldec's court, where he uses individuals with magical ability to carry out his nefarious plots and evil deeds. Constantly fearing for her life and unable to trust anyone, not even the Good Folk who are, themselves, magical and persecuted by Keldec, Neryn sets out on a journey to find Shadowfell and the secret rebel group that resides there, though she can't be sure it even exists. The journey pushes Neryn to her limits and brings unexpected people - and creatures - into her life; individuals that teach her about trust, love, friendship, and, most importantly of all, who she truly is.Like all good epic fantasy, Shadowfell's premise centers around the universal, recurring struggle of good versus evil. Though the reader never truly meets Keldec in Shadowfell, it's clear from Neryn's scrapes with his minions that he epitomizes evil. I'm really hoping to learn more about Keldec and his past in the next Shadowfell novel. As the reader learns in this first book, Neryn is a complex, layered character and I feel it's only fitting that the reader have clear understanding of her nemesis as well.I've always had a soft spot for the romance in epic fantasy. These romantic plot lines are usually slow building and filled with tension and complications. I honestly feel that if the romantic relationship between characters in epic fantasy develops easily, the author is doing something wrong. Marillier's romance in particular has always been a favorite of mine, so I wasn't surprised by the hurdles and difficulties placed between Neryn and Flint, who is an obviously perfect match for Neryn. As the first novel in the Shadowfell trilogy, readers can expect quite a bit of world building and character development. For me, epic fantasy requires trust from the reader and a willingness to embark on a multiple book journey. There are slower sections of Shadowfell, but they are not, at least in my opinion, boring. These sections that are slow in action feature heavy character development, which is just as important as a high-paced action sequence.I cannot recommend Shadowfell highly enough. Marillier is an extremely gifted storyteller and I'm always impressed by the depth and beauty of her writing. I have a strong suspicion Neryn and her journey will become one of my lasting favorites.