This is an audio-only release (for now anyway) about Peter (and Toby) go looking for a poltergeist in the stacks of the basements of The British Library. Harold Postmartin was hanging out at the Folly when Peter got the case, and wouldn't let him shrug it off for awhile, so he got to do a little field-work, too.
It was fun to see Postmartin in action and learn a bit more about him. Peter and Toby were their usual entertaining selves. The Librarian (who's name I can't remember, sorry), was fun -- the tie-in with Peter's family was, nice too. The Library (in both fact-based and clearly UF ways) was an interesting place, and I can easily see the need for Peter to return there on another case.
Holdbrook-Smith is just fun to listen to, if I heard another couple of books in this series, I'd probably hear him in my head for any future Peter Grant/Rivers of London books. Top-notch stuff there.
I gripe too much about short stories being to short, so I'll try not to here. This was a complete story, but it very easily could've gone on -- in fact when the file ended, I pretty much thought that my headphones ran out of juice. It was good enough to satisfy, but not so good that I can't grumble about it being short. This was fun, and though I'm not sure how giving a story away works to earn money for a library charity, I'll trust that it does some how and hope that it meets with plenty of success.