In reply to Tyler: Yes I was a bit confused too.
Tony told me this:
(Mike's original problem was called Serenity, Dan's 8B, the extra move into this, is called Serendipity)
Which I added in. However the exact details of this limestone roof are perhaps left enigmatic, as it makes it all, well, you know, that little bit sexier. Or something. Ok. maybe not.
Jack