I enjoyed the first half of this, and so hoped, as I picked it up again today, that it would not go into free-fall in the last half. it has not - if anything, this book gets better as it goes along. I think this one is much more interesting than what preceded it, The Cask. I like that Lois stepped to the fore and played amateur sleuth so successfully, even though this had been Inspector Tanner's show up till then.
in the next chapter or two, I should learn why Portugal factors into things, and why Tanner has gone there while I have been following Lois in her quest to break what seemed to me to be a perfect alibi.