Emereck the minstrel is traveling with Flindaran, a nobleman masquerading as a mistrel, when he discovers, in an abandoned castle, an ancient, and magical, harp. He would much rather have not found it, because all magic has its price. He has an obligation to bring it to the guild, though, and that means he has to deal with other people's desires surrounding it.
Because the Harp of Imach Thyssel can make a badly wounded man whole, or kill an entire city.
Emereck is plunged into the middle of politics he wants no part of, and is going to need to learn very quickly who his real friends and enemies are.
Neither the plot nor the worldbuilding are as strong here as in the earlier Lyra novels, but it's still an enjoyable plot that does keep moving, and I like the characters. The narrator does a fine job, too.