With the River's Flow

After their tractor breaks down and explodes, the brothers must finish the trek to Ishval on foot. In a nearby town Al criticizes Edward's rashness and poor planning and urges dealing with the homunculi before hunting Scar, and their argument escalates into a transmutation-fueled brawl that sends Ed storming off alone. Meanwhile Winry meets Sheska at Hughes' grave, and Sheska confides that she has been quietly investigating his death, trusting only Winry with what she found, not even Mustang.

Wandering apart, Al is approached from behind by the snake-chimera Martel, who admits she trailed the brothers to gather intelligence on the other homunculi. Al questions the point of her revenge, since it would waste the sacrifice of Greed and the chimeras who died for her, but she counters that a chimera has nowhere else to go. At Sheska's home, she reveals that Hughes was likely killed for uncovering a deep secret tied to the Führer's secretary, Douglas, the woman who ignited the Ishval war. Sheska notes Douglas supposedly died two years before the conflict, yet still serves and has not aged, and Winry proposes tapping her phone line.

Disguised in a borrowed uniform, Winry picks the locks into the underground line room, and their tap catches Envy contacting Douglas, who is Sloth, to complain about the northern mission. Sloth detects the static, and her full water form drives the terrified girls to flee; before Sloth can finish them, Winry sees the secretary wears the face of the Elrics' mother, Trisha, and Ross and Brosh arrive to force the homunculus back. Recalling Al ran toward a river once before, Ed finds his brother, the two reconcile and agree Scar comes first, and Martel drives them onward by motorcycle as Al privately vows to keep stopping her.

A quarrel over strategy splits the Elric brothers on the road to Ishval. Martel reappears and shadows Al to learn about the homunculi. Sheska tells Winry that Hughes died over a secret linked to the Führer's secretary, Douglas. Winry and Sheska tap the secretary's phone line and overhear Envy and Sloth. Winry discovers Sloth bears Trisha Elric's face before Ross and Brosh intervene. The brothers reconcile and continue toward Ishval with Martel.

The episode leads into the following installment, Secret of Ishbal, and advances the 2003 series' original plotline in which the homunculus Sloth mirrors the Elrics' mother, a thread unique to this adaptation.