The Shadows Upon Lassadar Series is a collection of games based in the world of Lassadar. The games are all solitaire, with the exception of the second which is solitaire or for two players.
In the first game, Shadows Upon Lassadar, the Grayking is trying to return to Lassadar after many years of being trapped in the Tower of Ash. In this solitaire game, you must defeat his servants and send him back to the tower, closing 3 Barrier Gates, using magic, without letting that magic corrupt your spirit.
In the second game (a prequel), Sorrow of Salilth, the Grayking has launched an attack on the city of Salilth. The Wardens of the Citadel must protect the city from being taken over by his servants and seal the gates they are using to enter.
The third game, Revenge of the Raven Consort, has the lover of the Grayking searching for books describing the creation of the Barrier Gates which keep the Grayking trapped in the Tower of Ash. You must find them before she does to prevent his return to Lassadar.