That was really helpful! Thank you!
I can't work out the next step either, though, so I think this Lion may defeat me.
Unfortunately, I think I'm just too much of a novice for this book. It's my first proper attempt at something that isn't out of a children's book, which was all I could previously find, and most of it completely stumps me. There's just not enough detail in the diagrams for me to work out what's happening, and the descriptions are poor. I bow my head in defeat.