Halo: Nightfall trailer sets a grim tone for the series

The trailer for the upcoming Halo series sets up a pretty grim atmosphere. Lieutenant Commander Locke is deployed to a distant world to investigate possible terrorist activity. Of course nothing is as it first seems, and soon Locke and his team are drawn into a much deeper plot.

This interactive series will be available through Halo channel, and viewers can complete challenges that unlock features in Halo games. Watch the trailer below, and tell us what you think about it.