Not the first time I've read this, and it does feel rather like a novella and a short novel lumped together, but that's alright, I still enjoyed it. I like the cleverness of it, the constant faking out of the Second Foundation (does it exist? where is it, exactly?) but towards the end it felt a little as if the well was running dry. You can only read "I know where it is! No I don't..." so many times before your ability to care starts to dry up as well. If I were rating on cleverness alone, this would likely be a four star read, but for me the characterisation drags it down a little. The Mule is always a fascinating figure, but he's long dead for most of this - the bulk of the story taking place a couple of generations after his time - and with the exception of Arcadia, all the other characters are pretty thinly drawn. And yeah, I get this is a series that relies on concept, on being unashamedly idea fiction, but when I can only manage to give a damn about one of a cast of a dozen or so, all the intelligence in the world can't fill the gap.