Ep 48. The Oath in the Tunnel

Edward and Alphonse are finally able to get out of the tunnel they were trapped in. They find themselves in a small village, where they encounter May Chang and her panda, Shi. The two are looking for the secret to immortality, just as the Elric brothers were looking for the Philosopher's Stone.

They all decide to team up and head to the nearest town, which is also the location of the South Headquarters of the military. The group needs to find out what happened to General Olivier Armstrong, who was sent to Briggs Fortress. They discover that the military is planning to use the ultimate trump card, the Philosopher's Stone, to defeat the homunculi. However, Ed, Al, May and Shi are skeptical, as they have witnessed the negative effects of using the stone.

As they continue their journey, they come across a group of Ishvalans who were forced out of their homeland during the Ishvalan Civil War. Ed and Al learn more about the atrocities committed during the war and their role in it as alchemists. This leads them to make a vow to help rebuild Ishval and make up for their past mistakes.

The group finally arrives at Briggs Fortress, where they meet General Armstrong's subordinate, Major Miles. They discover that the fort is being targeted by the homunculi and their minions. Ed and Al help defend against the attacks and successfully fend off the enemy.

However, when they return to the town, they find out that the military has already used the Philosopher's Stone, causing havoc and destruction. The Elric brothers are devastated and feel helpless, realizing that they couldn't stop the military from using the stone. Meanwhile, May and Shi have found the source of the immortality they were seeking, but they are unable to obtain it.

In the end, the group decides to continue their journey and head to the north to investigate the mystery of immortality, as well as to find a way to stop the military from using the Philosopher's Stone again. The episode ends with a scene of Ed, Al, May and Shi walking towards the north, ready for the challenges ahead.