Writers in the games industry often expect to be involved in the creation of sweeping story arcs that will cover 10, 20, 30 hours of gameplay. The truth however, is that there is a much stronger need for quality sub-narratives: side missions, quests, and parallel narrative arcs that become exercises in brevity and focus. The immersion provided by gaming has shown the medium is uniquely suited to benefit from the depth a strong sub-narrative can provide. This session focuses on hands-on principles gleaned from the creation of the parallel universe of Shangri-La from Ubisoft's recently released Far Cry 4, along with a look into the development of several Murder Mysteries from Assassin's Creed: Unity. This is an examination of tools game writers can use to ensure their sub-narrative contributes, and does not detract from, a healthy and immersive narrative world for the player.