The continuation of Lirael.
Much brisker and more story-like, given the set up in Lirael. Lirael and Sam set out, since the Disreputable Dog knows another way out of the House. It has its dangers. They head downriver into the place where Hedge is practicing necromancy to dig up something. An attempt to rescue Nick reveals a great deal of information but does not succeed.
The rest revolves about looking into the past, an assassination, the discovery that a powerful necromancer is now one of the Dead, a great deal of lightning, a permission letter from the government, refugees, and a lot more.