Titles and cover artwork for the sixth and seventh instalments of the best-selling A Court Of Thorns And Roses (Acotar) series have been unveiled by author Sarah J Maas.

Set across the courts of fictional Prythian, the popular "romantasy" books track teenage human huntress Feyre Archeron after she is brought into a perilous yet magical faerie realm. The upcoming releases follow A Court Of Silver Flames (2021).

The sixth book, titled A Court Of Splintered Harmony, features cover art with a pink and yellow ombre background showing burning flames over a bed of bones.

Bloomsbury will publish the work worldwide on 27 October, ahead of the seventh book’s release on 12 January next year.

It will follow the “insidious” threat of an immensely powerful death-God named Koschei the Deathless, and will depict part one of a big story titled The Valkyrie Cycle, whilst parts two and three will be covered in Acotar 7.

An untitled eighth book will cover part four of The Valkyrie Cycle.

The description for book six says: “The Night Court will not stand idly by while innocents are attacked.

“But with Prythian still piecing itself together in the wake of the devastating Hybern War, the task of uniting is proving more difficult by the day.

“To make matters worse, those who rule and protect the Night Court are reeling from recent betrayals and revealed truths. The rifts dividing them seem insurmountable.

“But to defeat Koschei’s creeping shadow, they must find a way back to each other and resurrect their former alliances.

“To survive, they must find a way to repair the splintered harmony all around them.”

The eagerly awaited book will be followed by the seventh instalment in the series, A Court Of Forgotten Melody, which features a yellow and aqua-blue ombre background covered by a spider-like figure.

“What was lost will be reclaimed. Prythian might never be the same again,” the description says.

The powerful Night Court appears to be under threat, and the book will see “traditional alliances crumbling” amid the pressure of a united front under “the continued threat of Koschei the Deathless”.

The description adds: “Bonds will be tested. Power will shift. And old enemies will emerge from nightmares of the past.

“As the Night Court’s Inner Circle disperses far and wide, desperate for any advantage against Koschei and his mighty allies, peace hangs by a fragile thread.

“But hope can be spun from the darkest of shadows, and the Night Court has its own part to play in the looming crescendo.”

Maas is also the author of the Throne Of Glass and Crescent City series, and her books have been a global phenomenon.

They have sold more than 75 million copies and are published in 40 languages.

The award-winning author previously announced her latest books on Alex Cooper’s Call Her Daddy podcast earlier this year, describing the new story as “really, really, really big”.