《艾笛的永生契約》作者V. E.舒瓦，帶領讀者重返幻色闇倫敦的魔幻世界
 
　　距離凱爾、萊拉、霍藍三人聯手，將歐薩隆這股邪惡力量打敗後，已過了七年。原本以為自此之後四個世界能漸趨平靜，然而白倫敦卻出現了新的「安塔拉」（能夠自由來往四個世界的人物），這個年輕的女王搶奪霍藍逝世後的政權，並不計一切代價，要恢復白倫敦的魔法，即便付出自己生命也在所不惜。
 
　　另一邊紅倫敦皇室，也就是凱爾的弟弟萊伊以及他的丈夫阿魯凱德，則面對一個全新的地下組織所引發的叛亂，試圖將整個皇室牽扯入一場大陰謀裡。此時此刻，行蹤不定的船長萊拉，以及深受魔力強大所帶來肉體折磨的凱爾，該如何和新朋友、老朋友們聯手，揭穿隱藏在四個世界背後的巨大陰謀，並保護他們所愛的人們呢？(文／博客來外文館)

　　V. E. Schwab, #1 New York Times bestselling author of The Invisible Life of Addie LaRue, opens another door to a new fantasy series set in the dazzling world of Shades of Magic.

　　Prepare for tangled schemes and perilous adventures with friends old and new in The Fragile Threads of Power.

　　Once, there were four worlds, nestled like pages in a book, each pulsing with fantastical power and connected by a single city: London. Until the magic grew too fast and forced the worlds to seal the doors between them in a desperate gamble to protect their own. The few magicians who could still open the doors grew more rare as time passed and now, only three Antari are known in recent memory—Kell Maresh of Red London, Delilah Bard of Grey London, and Holland Vosijk, of White London.

　　But barely a glimpse of them have been seen in the last seven years—and a new Antari named Kosika has appeared in White London, taking the throne in Holland's absence. The young queen is willing to feed her city with blood, including her own—but her growing religious fervor has the potential to drown it instead.

　　And back in Red London, King Rhy Maresh is threatened by a rising rebellion, one determined to correct the balance of power by razing the throne entirely.

　　These two royals from very different empires now face very similar struggles: how to keep their crowns—and their own heads.

　　Amidst this tapestry of old friends and new enemies, a girl with an unusual magical ability comes into possession of a device that could change the fate of all four worlds.

　　Her name is Tes, and she's the only one who can bring them together—or unravel it all.