For many months, Enclave and Brotherhood of Steel soldiers battled over settlements throughout the Capital Wasteland. One major battle saw the Brotherhood of Steel and Enclave lose a great number of soldiers. This was the Battle of Canterbury Commons. For months, the Enclave had been sending troops to the settlement of Canterbury Commons to negotiate a truce with Ernest Roe to halt caravan movements near Brotherhood of Steel occupied settlements. When Elder Lyons got word of this information, he sent a representative to speak with Ernest Roe. The discussion, Walton learned was to plan an ambush on the Enclave soldiers who would be sent to Canterbury Commons to accompany a caravan on its way to Evergreen Mills to pick up a shipment of the virus. Walton enlisted the aid of Tanya Christoff aka The Antagonizer to help with the attack on Canterbury Commons. Walton's plan was to send the the 2 or 3 soldiers as originally planned, but have a larger group of soldiers occupy the abandoned Robot Repair Center, power up some of the remaining robots and attack the Brotherhood of Steel soldiers when they arrived to attack the caravan. At 9pm on the day of the caravan movement, the battle began. Brotherhood of Steel soldiers move in to take out the caravan. At the same time, Enclave soldiers from the Repair Center opened fire on the advancing Brotherhood soldiers. Little did the Enclave know, there was a second team moving in from the other side of town. This team spotted the Enclave exiting the Repair Center and revealed their position before the whole forward advance team was massacred. The Brotherhood of Steel soldiers took cover in the diner and picked off any Enclave soldiers attempting to enter the settlement. As the Brotherhood then began to advance towards the Repair Center, Tanya Christoff and her small army of ants attacked from the South. Now being attacked from both sides, the Brotherhood was forced to retreat. The made their way North, and came upon a vault. They made their way inside and found Enclave equipment lying all over the place. They heard Enclave soldiers moving in from both sides and radioed in the position before the were killed. The message was brought to Elder Lyons who made the decision to send the Lyon's Pride in to investigate. After hearing about the Brotherhood's discovery of Vault 108, Dr. Walton decided it would be best if he started moving some of the science equipment to another location. Walton packed up his things and made his way to Fort Constantine. Things went downhill after the Brotherhood discovered Vault 108. Fort Bannister and Evergreen Mills were the next to fall. At the Battle of Fort Constantine, a large chunk of Walton's Enclave forces were wiped out. After months of moving around, Walton and the last remaining Enclave soldiers were holed up in Old Olney using the Deathclaw population to hold off any Brotherhood of Steel soldiers from trying to enter the settlement. Dr. Walton continued to develop the virus with only a handful of Enclave scientist and very little scientific equipment left. On October 19, 2278, the Brotherhood of Steel entered Old Olney under the cover of darkness and moved a few snipers into position. As the sun began to rise, the Enclave soldiers came out from their barracks and began checking their defenses. When they made sure their defenses were still intact, they informed Dr. Walton. Although he knew the defenses were intatc, he still wanted to make see for himself. At 8:14, he exited his office and at 8:15 a Brotherhood of Steel sniper took the shot. Dr. Sieze Walton was struck toin the chest and was killed instantly. The remaining Enclave personnel surrendered and were taken to the Citadel for questioning and then execution. It took months for the Brotherhood of Steel to distribute Walton's cure. His virus had affected almost half of the Capital Wasteland's population. By February 2279, Walton's virus was cleansed from the Wasteland and any trace of his existence was erased.