Only a week before the meeting of Mycetian League (Mushroom Planet people who live on earth), Mr. Bass receives a strange phone call from one of the League leaders. Mr. Bass, David, and Chuck hurry to Wales, where the meeting is to take place, and discover that the two most prized treasures of the League have been stolen. One, the Necklace of Ta (leader of the Mushroom people on Basidium), causes trouble whenever somebody takes any of its stones. The other, The Thirteenth Scroll, is the only key to the Mycetians’ past. Mr. Bass and the others go on a search throughout England to find the missing treasures and encounter mysteries from the past about Mr. Bass’ long lost Elder Grandfather.
This is the conclusion of the Mushroom Planet series. It’s also one of the more weird ones. Digging deep into Mr. Bass’ past, and even into the ancestry of the Mycetians makes for an interesting read. I highly recommend that you read the other books that come before this one, though. I hadn’t read two that came before this one, and it was kind of a shock to hear about people that were in previous books that I hadn’t read.