Chief Warrant Officer Mary Quan served as nuclear tech on the Lexington. She was staying in room 3E.
She had dated Special Ops guys once.
The protagonist noticed that during Mission 161 she seemed like a busybody and to love intrigue. She kept a diary when Hideki Miura told her that terminals can be overriden. In March 18, Jennifer Tran called a Nuclear Plant Casualty Drill during the first dog watch (which happened to be her sleep shift). Her Damage Control team didn't fare well but Quan suspected that Tran set them up, as she simulated a computer failure at the same time as the NPC. It took them ~9 mins to isolate and contain the failure and set Condition Yoke for the contaminated areas. Tran wasn't happy and reamed her team.
In March 21 she was in Engineering with Renato Olivar when James Poole started grilling him about the upgrades made to the Lexington during the overhaul at the McHenry yards. These questions made Quan to think that he was trying to get up to speed on his new assignment, if they weren't hinky.
On March 24 Tran ordered another nuke emergency drill, this time for a mock Nuclear Weapons Incident. David McClary was assigned to the Decontamination Station for Damage Control and had his hands all over her during the Decon segment. Her team did OK.
On April 8 she felt frustrated and upset, and all the tension on the ship getting worse. She also wondered why this hype with the science ship. On April 20 she heard about Poole's and Taewon Narang's heated discussion over the war and decided she didn't like Poole. On May 4, Quan observed him running around the ship like a caged rat.
On May 5 she and others went to the General Quarters at 14:07 because of an enemy vessel until 15:10. She understood that Poole was hopped up and perhaps knew about it before it happened.
On May 16 she realised that Poole was sleeping with Kimberly Falcon.
On June 10 one of the coolant pumps in Section 8 went out and the reactor temp started climbing. Her team got it under control and brought a back-up online.
On June 11 she caught Poole hanging around the entrance to one of the Weapons Bays and seemed guilty to her. On June 15 she followed him to Deck 2 with a bag, and saw he entered to Michael Dahl's room with an override code, while he was in the Medlab. He started suspecting him for a UN agent (or an Alliance Special Ops plant) and was convinced.