This nicely-done and copiously illustrated work offers a look at calligraphy alphabets beyond the usual Roman, Italic and Uncial. You get Celtic, Oriental, Greek, Hebrew, Cyrillic and more with details of how to cut and hold your pens as well as the letter shapes, and notes about the tradition in a variety of cultures.
I think it’s fair to say that this is something for the calligraphy enthusiast rather than the beginner or dilettante. You need to be comfortable with basic techniques (and Margaret has several books which will help you master those) before you try the less-familiar shapes that are shown here. However, if you’re looking for a way to expand your range, you’ll find a lot to explore and digest here.