The action ramps up in episode 4 of Halo 4: Forward Unto Dawn.
Szymon Biernacki's Concept Art for Halo 4: Spartan Ops
Here's some of the concept art work created by Szymon Biernacki for Halo 4: Spartan Ops.
Halo 4: Spartan Ops - Episode 5
Here is the fifth CG episode of Halo 4: Spartan Ops, created by Axis Animation.
Making Halo 4 - Part 1 and 2
Join 343 Industries on a 20 minute behind the scenes featurette on the creation of Halo 4.