Hi Everyone,
I've just finished Skull Castle(took me about an hour just to figure out how to get out!) and I'm wondering what I should go do next. Am I supposed to go to the shrine next?

Yep, the Shrine of Anephas is your next goal. Make sure you have the Staff of Death...you need it!

Cheers,
-Saz

Thanks, will do. Btw, is it possible to "vanish" to the Lost Sea area before going to the Shrine?

Yes, it is. Just sidle up to some trees that act as a barrier and then save. Cast Vanish until you pop over. You can also tree surf (now casting mystical signs in the direction of Sazerac) as shown here. Good luck!