The book is number 15 in the 43 book series. I collect and read children's books and in my opinion this is one of the best children's mystery series ever. In this book the 3 protagonists solve the mystery of what happened to the local ecentric potter. He disappeared and left his house empty.
The Potter's house is haunted!
The Potter is - or was - an eccentric old ceramics artist, famous for wearing a long white robe and going barefoot. A short time ago he mysteriously disappered. Now his house is filled with bare footprints that dance with ghostly green flame!
Has the Potter died and come back to haunt his house? His family fear the worst. But the Three Investigators have a different idea - because they aren't ready yet to believe in ghosts!