The Golden Skull Quest is started by asking Victoria the Sorceress about Chyloth. She tells you of the ferry man and how he can be persuaded to ferry people over lake Mortis by giving him a gold skull. The skull is obtained from the bone daemon, which she will summon for you, but she requires 1000 daemon bones to do so. Victoria will store the bones for you until you complete the task.

When summoned the daemon appears on a stone pentagram in a circle of stones

On the death of the daemon the gold skull will appear in your back pack This skull can then be given to the ferryman to gain access to the Gauntlet.