During the operation at Fort Anchorage, Alaska, Murphy was tasked in deactivating the base's atomic bomb. However, Murphy and his men, including Dr. Oppenheimer, were captured after being engulfed in a Chimeran airship. Inside, he and Alpha Team fended off hoards of arriving Chimeras and still planned on protecting the bomb and disposing it out of the airship. But, Murphy ignored their objective and seek in saving his men. In doing so, he revived Doctor Oppenheimer with a blood transfusion and told him to save himself and the others after he tricked everyone to go inside a tank and bail out. Following this Murphy sacrificed his life by detonating the bomb, destroying the airship in the process.
In Murphy's postmortem, he was criticized for ruining the entire mission in failing to obtaining the bomb and as well for the death of Oppenheimer, who passed away from the transfusion. However, Joseph Capelli strongly defended his superior as his death didn't go into vain as his actions destroyed the Alaskan/Russian ice-bridge and irradiated the entire area, making it impossible for the Chimera to cross over North America from Russia by land, and so saving the United States as previously aforementioned by Oppenheimer.
- Murphy was the first ever Sentinel leader.