Haven: Call of the King (2002)

King Athellion departed his home world to fight in an intergalactic crusade. On the Mount of Sighs, he left a giant bell, the Golden Voice, which was to be rung to call his return should he ever be needed. Many years later, an evil being named Lord Vetch enslaved Athellion's people, forcing them to work in his mines. To ensure their servitude, Vetch infected every slave with a deadly virus requiring a constant dose of antidote, the only source of which he controlled. (wiki)