Walkednights is one of my most popular free patterns. It currently has 61 projects on Ravely with very good Average Difficulty Rating. I think this is wonderful because Walkednights is not a typical standard crochet pattern. It is actually a "problem" or a "crocheting exercise" which crocheters need to figure out for themselves in order to complete the project.
The matching pair of intimate apparel (or swimwear) is completed by solving the problem: "Using the square motif and trim patterns given as theme, make a bralette and underwear set."