Thanos attacks the Grid!!
Thanos learns of the Grid and believes it may contain knowledge that he craves. He manages to access the Grid and wants to conqueror it al all costs.
NO infinity stones for Thanos here, but he DOES have his Chitauri forces backing him.
This is the Grid as of Tron Legacy. Assume Flynn, CLU, and Tron are still alive and will actively work together to defend the Grid against Thanos. Also assume they know Thanos is coming.
How does this go?