A Fire Emblem fan was recently looking at internal codenames for previous entries in the series and discovered that there is potentially another Fire Emblem game in development at Intelligent Systems that was being worked on after Fire Emblem Three Houses was completed. Fire Emblem Three Houses was known internally at Intelligent Systems as Iron17, and Fire Emblem Engage was known internally as Iron19, so that leaves only Iron18. It is thought that Iron18 could be Fire Emblem Genealogy, which has been rumored to be in development at Intelligent Systems for some time.