Sergio Ferrer wrote a book ALMILES and the current Work of art is related to the First chapter, Witches' sabbath.

"ALMILES, the discovery of connections between people. Artists, composers, musicians, writers, painters ... all of them are RECEPTORS of FEELINGS. They receive dreams, vibrations and simply write, compose or paint what they receive, but, does all this really come from a Muse, or is there something else?"

I. Witches' sabbath
Jack and Walter walk down the river Vero in Spain looking for the witch's cave, finally, the cave found them