Wotan's Fire

When Ingrid, Yoko's organist friend, invites her to a German castle, what are the chances it's merely for a concert? Among a collection of ancient instruments she is there to authenticate, Ingrid found a strange, technologically advanced device. It belonged to a physicist whose final work was, supposedly, a so-called 'death ray'. Trouble soon follows, and to prevent a mysterious gang from stealing the horrific technology, Yoko and her friends may have no choice but ... to use it.