The Prisoner's Throne (édition en anglais)

Prince Oak is paying for his betrayal. Imprisoned in the icy north and bound to the will of a monstrous new queen, he must rely on charm and calculation to survive. When High King Cardan and High Queen Jude go to extremes to retrieve their stolen heir, Oak must decide whether to attempt to regain the trust of the girl he's always loved or remain loyal to Elfhame and end Wren's reign - even if that means ending her too.

With a new war looming on the horizon and treachery lurking in every corner, neither Oak's guile nor his wit will be enough to keep everyone he loves alive. It's just a question of whom he will doom.