[quote]Like the Vex or Cabal invading Earth and you have to defend against their attack for x amount of time. Edit: wow this thread is tending now? Amazing! Hopefully Bungie reads it![/quote] Ive been on venus and earth when the enemy move against each other, if thats what you mean, you get right in the center and fight them off. As time progress's the enemies because noble, reaver, etc. After a while it stops though.