Commander DeSoto, call sign 'Mother Hen', was an Exofleet officer assigned to the Pirate Clans warship Avenger. Her sole appearance was in the episode Fireship.
Exofleet Intelligence received information from their secret Neo Sapien informant Marduk about a large underground complex of unknown purpose on Mars. The cloak capable Pirate warships Avenger and Cobra were chosen to insert three exosquads – Able, Delta and Echo – on a reconnaissance mission to determine the nature of the complex. DeSoto was the overall mission commander, while the Avenger and Cobra were captained by Neepo and Barca respectively.
The entry phase of the three exosquads into Mars turned out to be a deadly trap, as overwhelming numbers of Neo e-frames and Y-wings sprang up. As Delta and Echo Squads incurred increasing casualties, DeSoto recalled all the Exofleet survivors to the Pirate Ships. While Delta and Echo Squads complied with the withdrawal order, JT Marsh and Able Squad instead pressed on with the original mission and entered Mars airspace, pursued by Typhonus’s ambush party.
Able Squad eventually returned to the Cobra after Maggie Weston’s e-frame was disabled by Neo Y-wings. DeSoto was listening to Marsh’s suspicions that someone had betrayed the Exofleet’s mission to the Neos, when the comms feed was abruptly cut off. This was caused by the Avenger being destroyed by a bomb planted by the traitor Barca or his supporters. DeSoto, Neepo and the survivors of Delta and Echo Squads were all lost in the sabotage.