I have two mystery quilt books. Let me see if I can find them and give you the names of them....
Okay, I only found one, but the my other is by the same author, I think. The book is called Mystery Quilts by Rita Fishel. The book has 13 patterns in it. I bought it because I liked several of the patterns. One of my favorite is called What Knots. It works very well with one focus fabric, though it works well with just purple too!
Hope this helps some.
Dina