Episode 28: All Is One, One Is All (2003 series)

Izumi Curtis has decided to leave Ed and Al on Yock Island, an uninhabited island, which is the same place she left them during their training with no alchemy allowed hoping they can take the time to learn something. Winry can only watch as she, Izumi and Sig return to the mainland by boat. As they are walking both Ed and Al realize they are not the same as before since neither of them can no longer swim. Flashing back, the two remember the day where Izumi and Mason left them there for a one month evaluation test with the same rules to see if they are worthy of her training and leaves with the quote "One is All, All is One" pointing out they need to know the meaning to pass the test. In the present, Ed remembers how they had to work hard to understand it compared to now, unaware a mysterious figure is following them. They then arrive at the spot which served as their bed, which on the first night back then they were pondering what Izumi meant. It was also on that night that both of them had to deal with a mysterious masked man, who overpowered the boys and forced them to run away and hide. In the present, Ed notices some foxes as the mysterious person is continuing to observe them.

As the present Elrics catch some fish by having Al walk in shallow water without damaging his Blood Rune, they recall how they caught a bunny during their training days. Because of their hesitation to kill it, a fox to got hold of it, and then it injured Ed's original right arm when confronting it. Eventually locating the fox's nest and watching the fox give the rabbit to it's cubs, the past Ed and Al tried fishing instead. After several days they caught some, but the masked man scared them off. In the present, as Al tends to cooking the fish, the mysterious person is observing him and then Al accuses Ed of eating the fish when the fire is destroyed with only a hand print. After verifying to Al he didn't do it, the two go look for this mysterious person. In the past, the Elrics had to develop weapons and use other tools while avoiding the masked man, but with no luck and barely any food since the island's mushrooms they were finding are inedible. As the past Elric brothers are frustrated with their difficulties, the present ones are continuing their search and Al mistakenly thinks the stranger is Ed, shortly before the real one returns.

During an encounter with the masked man in the past, once Ed sees a dead cicada being devoured he realizes how important survival is and is able to convince the masked man to let Al go and leave. After talking it over with Al, Ed now recognizes how small his existence is, and even if he died his body would remain, it would eventually degrade as a part of nature which is part of a larger flow. Ed realized this was something that Izumi was trying to teach him since nature's flow and alchemy work together which is the answer for her question. The two then worked together and found the right mushrooms, as well as catch food, including killing a rabbit without hesitation for their remaining days of training before passing the test and moving on with their training. In the present, Ed realizes the point is to reteach them this concept, due to transmuting their mom as well as their present mission. After talking it over with present Izumi, who returned to the island with Mason, Ed decides to move forward. Once Izumi notices another present, the Elrics believe it could be the same masked man from the past. After Mason reveals he was that person due to Izumi sending him in secret to watch over the boys, the stranger, who is a boy comes out of the bushes.