An encore presentation of Chapters Seven and Eight of SILVER BROWN is showing at the Olde Zuckerberg Theatre, today being the opening day. At a rate of one page a day, as is the usual custom. In these chapters, the witch Florys MacNab visits a mysterious program called Yggdrasil, which (aside from the presence of some kind of tree) bears little resemblance to its mythological namesake. There’s at least one other allusion to the Icelandic sagas in the text somewhere, and a hyperintelligent puffin…