Secret Seven #10 Puzzle for the Secret Seven

The Secret Seven are siblings Peter and Janet, and Jack, Barbara, Pam, Colin and George. Together they are The Secret Seven - ready to solve any mystery, any time - in Enid Blyton's classic series of 15 mystery novels.
In book ten, the gang witness the horror of a house going up in flames. Then there's the theft of a very valuable violin. Are the two incidents connected?
The Seven mean to use all their detective know-how to find out!
First published in 1958, this edition features the original text and artwork.