The Princess of Convenient Plot Devices, Vol. 4 (manga‪)‬

Despite Rust Byrne’s warnings that their opponent is one of the powerful Adjutants of legend, Princess Octavia; her bodyguard, Klifford; and the young lord Derek follow the secretive noble through the passageways below the Sky Chamber, hot on the trails of the intruders who kidnapped Sil. Even during their rush, however, Octavia notices how clean the tunnels are, which begs the question—who could be using them and to what end? Meanwhile, Prince Alexis continues to be plagued by strange visions of King Eus, though they may be more than mere dreams…