The video above is the The Witcher 3 Wild Hunt The Cave of Dreams Secondary Quest Walkthrough and shows how to complete The Cave of Dreams, the quest featured in The Witcher III: Wild Hunt.
The video walkthrough covers the following objectives:
Join Blueboy Lugos and his crew outside the Cave of Dreams.
Explore the Cave of Dreams with Blueboy Lugos.
Face your nightmares in the Cave of Dreams.