Slightly clever, yes? Anyways, this is yet another Defend the Tower idea. Like Public Events, it'll spawn after a certain amount of time (20 minutes?). It'll start with an alarm sounding and instead of a navy blue fade-in, it'll be the red alarm sirens. "-Insert enemy type name- has invaded the City. It is advised that all Guardians proceed below and defend the people." A button will appear in the Ghosts menu to summon your ship - the same way you summon your Sparrow. You will have free reign to fly when err you want inside the Cities perimeter. Either you can fly around and shoot enemies and enemy ships or you can drop down and fight on the ground. The event will be cleared after a 10 minute countdown. The event will fail if every Guardian dies (they will have either one life or two). Rewards: Unique weapons/armor/sparrows/ships and two decoherent engrams or a rare chance for a legendary.