An urban spelunking group in San Francisco discovers a secret bunker belonging to the long-vanished 1930s stage magician Blackhall the Incredible at the same time as young, out-of-work magician Ivan receives a mysterious package that points him toward a possible conspiracy involving Blackhall's death in 1934. Both groups dive into the mystery, not yet realizing that it's about the change their lives forever.
Reunited with Backbone, Ivan must unlock the mysteries of Blackhall's legacy to find the final glowbug and take down S.P.I. once and for all. But will the combined forces of Backbone and the Nonchalants be enough to stop Sir Arthur? Find out in the stunning conclusion to THE LAST BROADCAST!