B'Eko was a female Klingon and a member of Klahb who participated in the attempted takeover of the Federation Embassy on Qo'noS. When Torvak, who was in control of the main computer and the security system in the subbasement of the embassy, didn't check in, B'Eko and Rov went to find him. B'Eko was left to protect Torvak from Worf who was loose in the embassy.
Eventually, Worf was able to get to the subbasement and reactivate the security system, flooding the building with anesthizine gas. It is unclear what the fates of Torvak and B'Eko were. (ST novel: A Time for War, A Time for Peace)