Here is the second CG episode created for Halo 4's Spartan Ops.
Halo 2: Anniversary - Remaking the Legend
See how 343 Industries have remade the legend of Halo 2 in this documentary video.
Making Halo 4 - Part 1 and 2
Join 343 Industries on a 20 minute behind the scenes featurette on the creation of Halo 4.
Halo 4 - Composing Worlds
This developer video for Halo 4 shows how the musical score was created for the upcoming sci-fi game.