Mace Flower serves as a flight attendant aboard the Haunzen Flight 356, a shuttle transporting Earth Federation officials and affiliates to the Adelaide Conference. Her duties include catering to passengers like Hathaway Noa and Kenneth Sleg, balancing efficiency with attentive service while maintaining a calm professionalism.

When hijackers disguised as the Mafty group seize control of the shuttle, Mace is drawn into the unfolding crisis. Amid initial violence targeting the crew, Kenneth Sleg shields her from harm. Turbulence from the hijackers’ docking capsule later hurls her into Hathaway Noa, who urges her to secure her seatbelt. Though appearing civilian, her covert role as an undercover officer emerges when she confronts the assailants, only to be swiftly overpowered.

After the shuttle’s forced landing in Davao, Mace aids in passenger evacuation and collaborates with Federation authorities during post-incident operations. Her dual identity as stewardess and operative underscores her part in the flight’s security protocols. Her origins, personal motivations, and activities beyond the hijacking remain undocumented in official records.