Meg, Jonny, Filch and Art, partners in The Invisible Detective series, try to connect Mr Frederick’s lost cat, a sudden plague of rats, and mysterious activity down in the sewer. What they discover is that a monster is haunting the drains, taking the local cats as food and causing the rats to flee before it.

This sequel is rather disappointing. As in The Paranormal Puppet Show, the device of the modern-day Arthur Drake finding himself remembering things which the 1930’s Art (Arthur’s grandfather, in fact) did, doesn’t seem to lead anywhere. The story is quite tame and doesn’t hold together terribly convincingly: why is the monster there? Why does Mr Fredericks ask the Invisible Detective for help at all? A lot of the appeal of the book is the quiet friendships between the children in the group, specifically, the way they look out for Flinch who’s homeless and support Meg whose father abuses her.

Tim Golden is a computer programmer living in London. He is also the editor of the Good-to-Read website.