I want to talk about the specific pleasure of a series that ends. Not a series that runs until the author stops writing but a series with a designed ending — a conclusion that was always the destination and that the preceding books were building toward.

The Patrick O'Brian Aubrey-Maturin series has 21 novels and was unfinished at O'Brian's death. The half-written 22nd novel is published in some editions as evidence of what was left undone. Reading it is an experience of approaching an ending that never arrives, which is appropriate and also painful in a way that completed series aren't.

The Discworld is complete. Le Guin's Earthsea is complete. Sanderson's Cosmere is not yet complete but is designed to be. I think about these as different kinds of projects — the open series as a record of a life spent writing, the closed series as a constructed object. I love both and I love them differently.