Whirl (Ondine Quartet #1), with its wonderful world-building, engaging characters and superb storytelling, was one of my favorite reads last year, so I was super excited to dive into the sequel, Billow. And I’m happy to report that the sequel does not disappoint in any way.Picking up six months after the end of the first book, Billow finds Kendra struggling to understand the role she must play as sondaleur, while dealing with the emotional and mental trauma of the devastating events in Whirl. Kendra must balance her chevalier training, fragile relationships and familial duties, all while an internal war wages within her. And when a rash of mysterious human and elemental kidnappings occur, Kendra and her friends find themselves battling dangerous Aquidae , as the Shadow looms ever closer. Kendra must choose her path and decide what being sondaleur really means.I loved Whirl because of author Emma Raveling’s ability to create an immensely layered and dimensional elemental world, full of engaging and likable characters, while offering readers a captivating and exciting story; all of which is deftly and effectively carried over into Billow. As a sequel, Billow seamlessly expands the story introduced in book one, while introducing new characters; new dangers and plenty of twists and turns.Perfectly paced, Billow flows effortlessly and captivated me from beginning to end. There’s a lovely and eloquent beauty to Raveling’s writing and she creates incredibly stunning images and palpable emotions with her words, yet her writing and descriptions never feel over the top or flowery. The world-building I loved so much in Whirl is laid out even further and deeper in Billow and the political/cultural/societal world of the ondines continues to be intricate, complex and intriguing. I’m still so impressed with how complete and real this world feels!Our heroine, Kendra, faces a very intense and raw emotional journey in Billow and I love how realistically she reacts to her situation. Kendra is far from perfect- she has a temper, she can be reckless and acts without thinking and is reluctant to ask for help, preferring to do things on her own- but this is what makes her and her story so relatable and easy to connect with. Kendra grows a great deal in this book, both as a leader and as a fighter, and her character growth never feels forced. This is a heroine that readers will not only relate to and love, but believe in.Two of my favorite characters from the first book, Julian and Tristan, continue to enthrall, enrage and excite me! Now, I’m not a fan of love triangles, but the complicated and often hot relationships between Kendra and these two guys never feels like a love triangle. You can feel the layered and tangible connection Kendra has to both of these swoon-worthy guys because Raveling has crafted them so wonderfully. And at this point I have no idea who I’m rooting for…I just lurve them both so much *sigh*The darker elemental powers and magic are explored more in-depth in Billow and this leads to some heart-pounding action and heart-breaking events. I really like the villainy of the Shadow and its Aquidaes because these are “bad guys” that aren’t just fun to hate, they’re actually incredibly fascinating.I love everything about how the book concludes- the tone, the twists and how it sets up book three. And I CANNOT wait to read book three!MY FINAL THOUGHTS: Billow took me on an exciting journey deeper into the complex and riveting ondine world that Raveling introduced in book one . With heart-racing suspense, excellent and believable character development, enticing romance and exquisite storytelling, this is a must read sequel in a must read series!