While it may seen strange to be holding a Houdini seance in May, in reality, Bess held many of her seances in the summer months. In fact, the first formal seance to be held on Halloween (that I'm aware of) was the Final Seance of '36. I can only assume until that time Bess keep her Halloweens private. So, yeah, a Houdini seance in May! I like it.
Thanks to Carl Morano for the tip.