|First appearance||Betrayal at Falador|
|Last appearance||Betrayal at Falador|
Shortly after the survivors' escape from the sacked monastery, Ebenezer and Castimir ignited one of Thorbarkin's bombs and threw it at the Kinshra that had gone in pursuit. It detonated and the explosion killed many soldiers and knocked many more off their horses, allowing the party to escape. Gaius's horse was killed by the blast and fell on top of him. He himself had been injured as well and took of his helmet to tend to his wounds.
On Doric's advice, Squire Theodore took Gaius as his prisoner to find out the Kinshra's plans, although the soldier weakly begged him for mercy. After his armour was removed, Gaius was put on a Kinshra horse and rode toward Falador with Ebenezer, who prevented all escape attempts by using magnesium and potassium to make Gaius think he was a powerful wizard, instilling him with fear. Upon arrival in Falador, Gaius was incarcerated in the White Knights' dungeons.
A couple of days later, Sir Finistere, concealed by darkness, arrived at night with fruit and meat for the prisoner. He told Gaius that he would help him break out soon and that he needed him to convey a message to Lord Sulla, to which Gaius smiled. The next night, Finistere returned with more food, they key to his cell and the key to the guards' room and told Gaius that he would need to count to hundred ten times after the watch change, leave his cell, put on the messenger clothing in the guards' room, the message for Sulla in the satchel, kill the drugged guard there, follow a guide to the stables and ride the horse waiting for him out of the city.
The next night, Gaius acted as Finistere had told him, although he stopped counting a bit earlier. After escaping to the stables, the stable boy brought him to a saddled brown mare, which had been moved. Upon leaving White Knights' Castle, he told the second guard he encountered on the bridge that he was to deliver another message in Burthorpe, after which he was able to ride to the city's north gate. Meeting no resistance from the guards there, he triumphantly laughed as he rode out of the city.
Siege of Falador
Three miles north of Falador, Gaius met with Sulla and delivered Finistere's message, with detailed how he would signal them from a building in the city. He pinpointed the building and informed his lord that it was the almshouse. He was ordered to make arrangements to keep eyes on the house at all times, after which Gaius left.
The next night, Finistere appeared and conveyed a message to Gaius and the knights on watch regarding Sir Amik Varze's plan to secretly lead his cavalry from the Falador Swamp in the west in an attack on the Kinshra, and informed Sulla of this gleefully when the latter visited him with Jerrod. Using this information, Sulla redeployed his troops and led the Faladian cavalry into a trap the next day as the Siege of Falador began. Only due to the sacrifice of Colonel Payne and the Falador City Guard were some of the knights, including a grievously wounded Sir Amik, able to retreat to the city, with Sulla's intending that they serve as evidence that all hope was lost. Gaius was part of this attack, being part of a regiment of lancers that squeezed in on the White Knights.
Later, when the White Knights charged northward from the city directly, Gaius led four hundred mounted pikemen from the east to intercept them. However, the White Knights, led by Sir Amik's valet Bhuler who was disguised as Amik to raise morale, slaughtered the Kinshra infantry and sent them fleeing so that they would come between the two cavalry forces, preventing Gaius's lancers from fighting without riding down their own foot soldiers. Realising what was happening, Gaius bitterly cursed and gave the command to charge at the Kinshra infantry and attack the White Knights.
Because the infantry men attempted to save their own lives, Gaius's cavalry lost speed and momentum, making them vulnerable. Bhuler and Sir Vyvin led the attack as the lancers were massacred, with Gaius bestially bellowing at his men to keep fighting. While he was distracted, however, he was struck by a sword beneath his arm, inflicting a mortal wound. He was shocked to realise it had been a twelve-year-old peon that killed him as he fell from his saddle and died.