Leading into Halo 4 itself, Halo 4: Forward Unto Dawn tells the story of Hastati Squad, a group of young UNSC cadets training to fight Insurrectionists just before the Human-Covenant War kicks off.
You can check out the first full episode here or below:
Very well done. I absolutely love the costume and armour design, so authentic, and I really enjoyed the nods to the expanded universe. Halo 4: Forward Unto Dawn is being told over five parts with a new episode airing each Friday leading right up to the launch of Halo 4.