He can be found inside Vittoria Vici's House in the city and not only does he share a house with her, they also sleep in the same bed, despite the fact that Vittoria Vici is betrothed and planning to marry Asgeir Snow-Shod. This suggests that marriage with the latter may be more of a political arrangement. If Vittoria Vici is killed during the Dark Brotherhood quest "Bound Until Death," Aquillius will also start to appear outside the East Empire Company Warehouse in the small hut on the left, where Vittoria would normally work during the day.