The HST quilt Exploding Star does not look quite the same to me as the one on the front of that book, which is made with 60 degree triangles. I had to greatly enlarge my screen to see that, but it's definitely not HSTs. It's a similar effect, but not exactly. I don't have the pattern, but it looks as if it would work a lot like the HST designs that are called value quilts, where you start by pairing the lighter and darker triangles and then just keep arranging them until you get the design you want. I'm sure it would be a lot more challenging with the 60 degree angles than with HSTs. The Exploding Star design is different in that it has a lot of all dark and all light squares included that are not pieced with triangles. Both designs are pretty.