The trailer itself shows Blood Ties, a new story-based mission that allows the player to explore Croft Manor, the mysterious home of the game's title character Lara Croft. It also shows Lara's Nightmare, where the manor comes under attack from zombies. Yes, zombies.
Both of those new content additions will be available for people who purchase the Rise of the Tomb Raider Season Pass for $29.99, which already includes access to two previously released DLC expansions. It will also throw in a two-player co-op version of the game's Endurance Mode, along with a "Extreme Survivor' difficulty level, and more character skins and outfits. All of this will be released on October 11.