Princess Luna still feels alone, nineteen years after her return to Equestria. When she finds a friend in an online game, everything seems better. But not all is well in Equestria, and a sinister plot threatens everything that Luna holds dear...
Drafted into the defense of Equestria, the Crusaders volunteer to embark a series of dangerous operations behind enemy lines to cripple one of their chief technological advantages, a revolutionary spell matrix that Twilight refers to as the "radio."