Fire Emblem: Awakening is getting more free game content, this time using the 3DS SpotPass feature. The first one titled "A Hard Miracle" is available today, and involves Chrom as he helps a mysterious woman rescue a group of kidnapped villagers.
Nintendo is planning more of these episodes to roll out over the next few weeks: "Ghost of Blade" on March 28, "The Wellspring of Trust" on April 11, and "The Radiant Hero" on April 25. These will be interspersed with extra weapons, playable characters, and challengers for the Double Duel mode.
These episodes shouldn't be confused with the downloadable content found in the Outrealm Gate. Instead, you just need to make sure that SpotPass is enabled and then go into your Bonus Box to find the extra maps. They'll have been automatically downloaded if your 3DS was connected to a wi-fi point.