In my opinion, Heroes doesn't need a super-amazing plot. The one it has is quite sufficient. You'll mostly be playing in multiplayer and single-player modes, not in the campaign. We'll see how it will be in the sixth installment (if there is one).
Bow down and hear our cry,
Our earthly rulers falter,
Our people drift and die,
The walls of gold entomb us,
The swords of scorn divide,
Take not thy thunder from us,
Take away our pride.
G.K. Chesterton: English Hymnal