Plot: Augusta Treverorum (365 AD)
Arriving at the base, which turns out to be the base camp of Division V, they meet Marcus and a female companion. The heroes are just able to talk to them through the transparent energy doors of their cells when an alarm sounds through the building. The AI has managed to man a temporal droppod and escape to an unknown time.
Marcus is able to follow the trail to about the year 365, to the Roman city of Augusta Treverorum. In the absence of active agents at the base, Marcus accepts the heroes' offer to search for the AI once more. Along with this comes the offer to become agents of the NEXUS if the mission is successful.
So the heroes, equipped for the 4th century, set off into an unknown scenario. Armed with pilum and gladius, they enter the teleporter and appear in a meadow in the spring of the year 365, before present-day Trier.
Once there, however, the search is abruptly interrupted when a centurion of the legion summons them to a battle at a villa rustica. There they first deal with driving some Franks off the land of the Roman commander in Gaul (whose Villa Rustica it was).
After the victory over the Franks, one could now turn to the search for the AI. Following the Omnisensor, the heroes now reached the city itself. There they found a fragment of the AI in the temple district of the city. The other fragment was in the room of Jerome, who was in the city at the time. Apparently Siri/Gladius had spent some time whispering some "visions" to the church father.
After both parts had been conquered, they returned to the base to the applause of the other agents who had returned in the meantime. Due to the great success, a final mission was to decide on membership of the NEXUS.