So, you think you've got the brain-power to tackle tough puzzles? Well, try this extraordinary assortment of mind blowing challenges. Divided in six different categories (geometric silhouettes, paper, laces, 3 dimensional, wires, permutation), they focus on different skills of your brain. Whatever their form, each is designed to stretch your mind to the max. Some of them are so complex that even the most expert puzzle sleuths may have to beg for mercy! Fortunately, solutions for every puzzle are included, along with explanations of how the solutions are reached.