Elizabeth Morgernstern was an unseen villain on the Babylon 5 episodes Moments of Transition and No Surrender, No Retreat.
A member of EarthForce, Morgenstern remained loyal to the tyrannical President Morgan Clark. In 2261 she was part of a task force led by Captain Trevor Hall to blockade the breakaway human colony on Proxima III until they surrendered to the Earth Alliance. Along with Hall, Morgenstern carried out orders to destroy civilians attempting to flee the blockade, resulting in the deaths of over 10,000 innocent people.
When John Sheridan learned of the attacks, he knew the time had come to force Clark out of office. Sheridan learned that Morgenstern had participated in the attacks on innocent civilians while other Captains such as Edward MacDougan went out of their ways to avoid carrying out orders targeting civilians.
Heading to Proxima III, Sheridan and his forces engaged Hall's task force. The Vesta and Furies stood down rather than fire on Sheridan, and the Juno bolted from the system. Morenstern had the Pollux engage Sheridan's forces, eagerly attacking his White Star ships and starfighters.
The Pollux engaged two White Stars. Hit by the Pollux's forward batteries, one of the White Stars spun out of control and collided with the Pollux. The resulting explosion destroyed the White Star and caused the Pollux to go zero g as her rotating section stopped spinning. Morgenstern and her crew were unable to reach the escape pods. Both she and her crew perished when the Pollux exploded a few seconds later.