Aware that Duke Larg is aiming for the throne, Glevanne conspired with Larg and his sister Queen Louveria to kill Princess Ovelia, the obstacle to Larg's claim to the throne. He proposes that knights of the Order of the Northern Sky wear the uniform of the Order of the Southern Sky, and kidnap the princess from Orbonne Monastery. This would put the blame on Duke Goltanna, and the Council of Nobles would favor Larg.
However, this plan did not work due to Delita Heiral's intervention. He was sent to rescue the princess by Baron Grimms of the Blackram Knights, also in the disguise of the Southern Sky. He personally brought the rescued princess and a captured Northern Sky knight to Goltanna. He frames Chancellor Glevanne in front of the duke, Bishop Canne-Beurich, Cidolfus Orlandeau, and Orran Durai. Glevanne denies the claim to no avail, and is executed by Delita.
It is never explicitly shown whether Glevanne truly conspired against Goltanna, or whether he was framed by Delita in a ploy to garner Goltanna's trust. The only evidence offered up against him is the testimony of Delita's prisoner, after which Delita also acts as his jury and executioner. After revealing the treason, Delita kills Glevanne quickly, before the chancellor is allowed to say much in his defense.