This is a moderately difficult adventure for 2+ characters. The players should be equipped in some way in advance to deal with spirits. The GM is also encouraged to create detailed maps and other props to assist players in visualizing the adventure.
BPI: If the characters are agents of the BPI or Sedgewick Society investigators, they may be called in due to the strange nature of the situation.
Hired: The characters may have been brought in by law enforcement to help with investigations.
Serendipity: The characters may have detected one of the “peripherals” themselves and began an investigation of their own.