At first glance, this looks like a children's book. 
 But if you look at the skull in the mountainside, and the title... not so much. No, "The Truth Is a Cave in the Black Mountains: A Tale of Travel and Darkness with Pictures of All Kinds" is one of Neil Gaiman's many short stories, here fleshed out with Eddie Campbell's odd assortment of illustrations and comics -- a dark, murky little tale of Scotland, revenge and the fantastical. 
 An unnamed Scottish dwarf approaches a former reaver, Callum MacInnes, to help him find a certain cave on the Misty Isle. The cave is said to be filled with gold, and only a few people can find it. The two men journey to that island and make their way to the cave -- but Callum warns his employer that the gold inside has a strange curse on it, which makes everything in life "less." But the dwarf's goal isn't mere gold -- he wants revenge, and he will do whatever it takes to get it. 
 Neil Gaiman is one of the greatest storytellers alive at telling us tales of dark, strange places occupied by otherworldly creatures. "The Truth Is a Cave in the Black Mountains" is a sort of fairy tale, and it's a picture book... but it's not really the kind that you give to kids. Oh, a kid could read it, but it's a very dark, grim tale about poetic revenge, murder and a very spooky cave-dwelling creature. 
 This is also one of those stories that could be set in any time period or any place. Gaiman chooses the Jacobean era of Scottish history, with the dwarf's excuse that he wants the gold so he can help restore the King Over The Water. Lots of windblown heather, mist, stony cliffs and a hint of faery goings-on (the protagonist refers to his father as being "from the West," and I don't think he meant the Americas). 
 One of the most interesting aspects of the story is that Gaiman keeps you guessing what exactly is going on throughout the story. It's obvious that SOMETHING is unsaid between these men (especially when Callum threatens the dwarf with a knife while he's sleeping) but he 
 And since this is a short story instead of a full-length novella, Gaiman's work is augmented by Eddie Campbell's illustrations -- sometimes it's just a swath of color, sometimes pictures, and sometimes he even creates little graphic-novel panels. 
 And those pictures bring an extra splash of life to "The Truth Is a Cave in the Black Mountains: A Tale of Travel and Darkness with Pictures of All Kinds," a powerful little story from a master storyteller. Just don't tell it to your kids before bedtime.