The fourth Millennium book and the first by a different writer, which is the whole question hanging over it.
It is more disciplined than the originals. Tighter plotting, fewer digressions, considerably less of the furniture-shopping detail the earlier books were mocked for. What goes with that is the strangeness. Lisbeth is handled more carefully and is less unsettling for it.
A competent continuation rather than a continuation of the thing that made them work.
Read April 2016.