The Undreaming is a mysterious force or entity. Mentioned by the monks at the Tibetan monastery, it is seen only once in Dreamfall, at the beginning when Brian Westhouse is sent from Stark into the Storytime. He meets the Vagabond who asks how he got there and then demands that he leave because otherwise something will find Westhouse in there. As Brian watches, a black mist appears from the sky overhead and attacks him - a mass the Vagabond names the Undreaming. What happens to Brian afterwards has been the subject of much speculation, as is the nature of the Undreaming itself.
A drawing of the Undreaming can be found in Faith's room in the Saint Petersburg laboratory. When Zoe Castillo enters the Storytime, the Vagabond asks her to tell him her own story, and she must hurry, because the Undreaming is unchained. The only other mention of the Undreaming is a sentence at the end of the credits repeating that 'The Undreaming is unchained', but what this phrase means is a mystery.