(Capcom's primary storyline)
Cartwright was part of the G-Virus research Senior Staff under the supervision of Dr. William Birkin. At some point during the course of the research, he had been appointed as the new team boss after his predecessor was ousted from office due to his negligence in security at NEST. His new position, however, led Cartwright to disagreements with at least two scientists, Rick Mendoza and Wayne Li.
Between August and September 1998, Cartwright was having trouble ensuring the security of NEST due to increased of the number of spies they captured. He was then ordered by Dr. Birkin to further intensify the security of the facility and if did not resolve this issue for good, he would lose his position as chief researcher. After being informed that the west area would be restricted for greater security, Cartwright was also entrusted to ignore all requests from Umbrella HQ for information about the G-Virus on the grounds that these procedures would do nothing to speed up the project.
Raccoon City Incident
During Operation: NESTWRECKER, when the USS began shooting Umbrella employees in the facility, Cartwright presumably hid in the midst of the attack to survive and due to the ongoing chaos in the NEST caused by the leak of the t-Virus at the facility, other scientists were having trouble locating him in order to use his ID Wristband to operate the bridges because the anti-infection lockdown.
Meanwhile, the other members of the greenhouse team were tackling the Monster Plant they were working on, and made plans to kill it with poisons. Eventually, Cartwright had been found by Dr. Mendoza and would help the team's survivors try to kill Plant 43 with the herbicide, but they failed and all were subsequently killed. His corpse was found near the body of Mendoza, who was still clutching Cartwright's wristband.