Mark Seibert is a games director, composer, producer and designer. Seibert has been working with Sierra, Sierra Entertainment, Sierra On-Line and Assemble Entertainment. Seibert's first published game was Police Quest II: The Vengeance released in 1988. After that, Mark Seibert took part as the composer of Quest for Glory: So You Want to Be a Hero. Afterwards, Mark Seibert worked on Torin's Passage developed by Sierra in 1995. Most lately, Mark Seibert worked on King's Quest: Mask of Eternity.