The Mystery of the Hasty Arrow

It is the noon hour at a museum in New York City. The date: May 23, 1913. The weekday, attendance is light; the attendees are scattered between two floors. Suddenly a cry rings out from the second floor. Scrambling to Section II, the museum director discovers a teenage girl dead with an arrow through her heart. An older woman hovers over her whispering incoherent phrases in the girl's ear and offering incomprehensible answers to the director's questions. She is the only witness to the crime, or accident, as the case may be. How will the feeble, 83 year-old Mr. Gryce unravel this mystery when this witness is apparently insane?