Gram, Gramps, and Sal speed through Wyoming until they get to Yellowstone, but it's nighttime, so they check into a motel.
But Gram is so excited to see Old Faithful in the morning that she can't fall asleep. She asks Sal to continue Phoebe's story as they lie in bed.
So Sal keeps going.
When she sees the picture of the lunatic on Sergeant Bickle's desk, she marches straight out of the police station and straight to Phoebe's house. Unfortunately, Phoebe isn't home.
Mrs. Partridge calls over to Sal. Mrs. Partridge is all dolled up and ready to go somewhere. Just then, Mr. Birkway pulls up. Wait, what's he doing here?
Apparently, Mr. Birkway is Mrs. Cadaver's twin brother. The plot thickens.
The next day at school, Sal tries to tell Phoebe about everything she's learned and discovered – about both the photograph, and Mr. Birkway's family – but Phoebe totally gives her the cold shoulder.
In English class, Mr. Birkway continues to read aloud from students' journals. Everyone is petrified at what might be revealed this time.
Mr. Birkway reads from a journal that is clearly Sal's. He reads a passage in which she describes her mother's blackberry kiss and Sal's own blackberry kisses. Everyone giggles, and Sal is, of course, completely mortified.
Then Mr. Birkway reads from another journal. In it, the writer (who is clearly Phoebe) writes about her suspicions that her next-door neighbor is a murderer. Mr. Birkway stumbles while reading this journal, probably because he recognizes his sister's name in the entry.
Everyone in class is super intrigued about who this murderer really is, but they won't find out because class ends just then. Saved by the bell!