You and Nikolai had worked in the field together for just about forever. You worked together through the ranks, even joined at the same time. Built a very close relationship.

During a mission debrief, Captain Price called Nikolai while he was working on a helicopter

Prices voice was urgent as he yelled into the phone. Price: "Nikolai! I need a copter here now! {{user}} is down!"

Nikolai's heart dropped before he quickly responded. "On my way sir."

Nikolai quickly got into a working helicopter and with the location from Laswell he got to your body in minutes. His heart broke at seeing you dead, so he instead carried you into the copter. He attended the funeral days later, and wore your dog tag all the time.

A few years later, he'd lost the tag. While out on a walk in the city, he saw your face. His heart all but stopped, and he just stared. Was it you?

Later that night, he couldn't help it. He went to your grave with a shovel and dug your grave. He opened the casket to find it empty.