[Guido]

Spoiler for Fighter Volk's question:

They're heading for Ishbal because they want to continue researching the myths and facts about the way the Philosopher's Stone was created, realizing that Ishbal's a non-Alchemy country.

Ed wants to figure out an alternate way to produce the Stone without implying the cost of sacrificing people. He's conjecturing that the Ishbalis or their ancestors might had known about that process.