From Dreamwalker: Roleplaying in the Land of Dreams Introduction:
Humanity is under attack. The enemy is an alien species that assails us in our most vulnerable state — while we sleep. The Taenia Spiritus are a race of soulless, hive-minded creatures that invade our dreams in order to foster and feed off the negative vibes and emotions caused by their presence.
You are a Dreamwalker. Whether through the use of drugs, prayer, meditation or natural ability, you are able to leave your own dreams and travel into the Dreamworlds of others. Once there you can manipulate the dream’s spiritual energy, or mana, to produce wondrous effects. You have been recruited by Project Dreamwalker — a government backed organization that unites others like you in order to rid the spirit world of the Taeniid plague. The task is difficult. Not only do you face the Taenia but you must also
satisfy the whims and desires of the Dreamer in whose mind they are ensconced. Can you do this and still maintain a grasp on your own sanity?
Good luck, Dreamwalker. You may be our last hope.