Unfortunately, it looks like #13 is not working. I was certain I found the solution, but it just wouldn't advance. I finally broke down and looked it up (which I was loathe to do), and I saw a video where someone did advance to the next level with the exact same solution I got. I'll have to let the author know that #13 is glitchy. I had no problems with #11 and #12. Hopeful for #14 and #15.