From amazon.com:

The capital has fallen. The Darkling rules Ravka from his shadow throne.

Now the nation's fate rests with a broken Sun Summoner, a disgraced tracker, and the shattered remnants of a once-great magical army.

Deep in an ancient network of tunnels and caverns, a weakened Alina must submit to the dubious protection of the Apparat and the zealots who worship her as a Saint. Yet her plans lie elsewhere, with the hunt for the elusive firebird and the hope that an outlaw prince still survives.

Alina will have to forge new alliances and put aside old rivalries as she and Mal race to find the last of Morozova's amplifiers. But as she begins to unravel the Darkling's secrets, she reveals a past that will forever alter her understanding of the bond they share and the power she wields. The firebird is the one thing that stands between Ravka and destruction - and claiming it could cost Alina the very future she’s fighting for. Ruin and Rising is the thrilling final installment in Leigh Bardugo's Grisha Trilogy.

From amazon.com:

Surrounded by enemies, the once-great nation of Ravka has been torn in two by the Shadow Fold, a swath of near impenetrable darkness crawling with monsters who feast on human flesh. Now its fate may rest on the shoulders of one lonely refugee.

Alina Starkov has never been good at anything. But when her regiment is attacked on the Fold and her best friend is brutally injured, Alina reveals a dormant power that saves her life—a power that could be the key to setting her war-ravaged country free. Wrenched from everything she knows, Alina is whisked away to the royal court to be trained as a member of the Grisha, the magical elite led by the mysterious Darkling.

Yet nothing in this lavish world is what it seems. With darkness looming and an entire kingdom depending on her untamed power, Alina will have to confront the secrets of the Grisha… and the secrets of her heart.

From amazon.com:

Hunted across the True Sea, haunted by the lives she took on the Fold, Alina must try to make a life with Mal in an unfamiliar land, all while keeping her identity as the Sun Summoner a secret. But she can't outrun her past or her destiny for long.

The Darkling has emerged from the Shadow Fold with a terrifying new power and a dangerous plan that will test the very boundaries of the natural world. With the help of a notorious privateer, Alina returns to the country she abandoned, determined to fight the forces gathering against Ravka. But as her power grows, Alina slips deeper into the Darkling's game of forbidden magic, and farther away from Mal. Somehow, she will have to choose between her country, her power, and the love she always thought would guide her - or risk losing everything to the oncoming storm.