Fullmetal Alchemist: Brotherhood - episode 51 - 03 Apr, 2010

As Edward's group arrives at the door where Alphonse had fought against Lust, the mannequin soldiers emerge from it. Meanwhile, Olivier is attacked by Sloth, who had been ordered to kill her. Alphonse and Heinkel learn too late that Pride had been sending a morse code message from banging a stick onto Alphonse's head, and they are soon attacked by Kimblee, who frees Pride from his imprisonment. In the sewers, May is also attacked by the mannequin soldiers, and when Envy manages to merge with them, he returns to his regular form. As Olivier struggles against Sloth, Armstrong rescues her and joins the fight. Alphonse transmutes his legs off in order to help Heinkel, who then gives him the philosopher's stone that Kimblee had previously lost. Alphonse uses it to restore his legs, and then he faces against Pride and Kimblee. (Source: Wikipedia)