Madeline Bergman is the woman in charge of the Bottle Ship research facility in Other M. She is first mentioned at the end of Sector 1 (Biosphere), when Maurice is recovering data from the Bottle Ship's computer. Madeline appears at the end of Sector 2 (Cryosphere), when Samus finds Maurice frozen to death. Samus notices that a woman is watching her, and gives chase. Samus soon finds out the the women is unwilling to cooperate with the Galactic Federation after watching one officer shoot another. Samus is unable to question the women any more as the Cryosphere's boss appears. However Samus on her way back to Sector 3 (Pyrosphere), questions whether the woman is actually Madeline Bergman. Samus, upon following a lone Federation Trooper to the Bioweapon Research Facility, encounters the woman again, who now introduces herself as Madeline Bergman after Samus assures her that they're on the same side. The woman claiming to be Madeline explains that the Federation secretly created a special forces program, based on the Space Pirates, as well as cloning Metroids from the remains taken from Samus's Power Suit. She tells Samus that the Metroids, along with the artificial intelligence controlling them, MB, are in Sector Zero.
Much later, however, another woman calling herself Madeline Bergman appears; it soon becomes apparent that this is the real Madeline. The woman that Samus encountered earlier was none other than MB's android form, created so that the infant Metroids would recognize her as their mother. Madeline explains that as MB interacted with the Metroids, she began to develop emotions and contradict the Federation's plans; thus, the Federation decided to reprogram her. Madeline had previously told MB that her initials stood for "Melissa Bergman", which made MB think that Madeline was calling her her daughter. When Madeline could do nothing but watch as MB was restrained, a disturbing reaction took place in the android; she rebelled against the Federation and used her telepathy to order the special forces to revolt. Madeline was the only one who managed to escape, and she sent out a distress signal, calling Adam Malkovich and his unit, along with Samus, to the Bottle Ship.
Shortly after Madeline finishes explaining all of this to Samus, MB herself appears with a Freeze Gun, intent on taking revenge. Madeline pleads with MB to stand down, but MB refuses until Madeline calls her "Melissa" again. Moments later, though, the Federation army arrives, firing their Freeze Guns; MB pushes Madeline out of the way and takes the blow for her; shortly after, she unfreezes herself and tosses her Freeze Gun to Madeline before calling the powerful Desbrachians to attack the Federation soldiers. Samus aims at MB to stop her, but it is Madeline who fires the Freeze Gun. An unnamed colonel then gives the order to finish MB off, causing Madeline to break down sobbing over the fact that her surrogate daughter has died. Samus attempts to comfort Madeline, but the colonel refuses to allow Samus contact with her. However, Anthony Higgs, revealed to have survived his encounter with Ridley, uses his orders from Adam and the Federation chairman to secure Madeline's safety. In the ending, Samus, Madeline, and Anthony return from the Bottle Ship on Samus's ship, Madeline falling asleep.