(Covers information from Anderson's universe)
During the outbreak in Raccoon City, Nicholai, alongside Carlos Olivera and Yuri Loginova, campaigned against the growing legion of undead in an attempt to secure safe passage for the uninfected civilians. After disobeying a direct order to return to base and leave a panicked woman atop a business building for dead, the three men were rejoined with their comrades on the ground below to continue on the fight. After Yuri is infected, they attempt to secure an extraction point for themselves, but their signals for rescue are ignored by passing helicopters.
When Yuri becomes a zombie, Nicholai has no other choice but to kill him after the zombified Yuri bit and infected Carlos. The two remaining men are left to wander the streets, searching for a way out. Nicholai is confused as to why Umbrella couldn't see their signals for help, though Carlos believes they did and simply left them for dead, citing that they were "expendable assets" of the company. The two are later recruited by Charles Ashford to rescue his daughter, Angela Ashford, in exchange for a way out of the city.
While Nicholai was a member of the U.B.C.S., his character in the film is radically different than his video game version. Unlike his video game counterpart, a self-serving operative, Nicholai's character has a deep sense of loyalty and right and wrong. Upon introducing himself to Jill Valentine in the school Angela was hiding in, he considered himself a "freelance" agent after the betrayal of Umbrella.