Avery looks up the fruit of the poisonous tree doctrine. It’s a legal rule that says that evidence obtained illegally is inadmissible in court. After school, she returns to Toby’s wing of the house to look for clues, joined by Jameson. She finds an old law book; on the page about the fruit of the poisonous tree doctrine, certain letters and numbers are blacked out to create a coded message. Avery realizes that the cipher disk she found in Toby’s wing can be used to decode it.

Jameson joins Avery as she decodes the hidden message in the lawbook using the cipher disk. It reads:

“Secrets, lies,

All I despise.

The tree is poison,

Don’t you see?

It poisoned S and Z and me.

The evidence I stole

Is in the darkest hole.

Light shall reveal all

I writ upon the…”

Jameson and Avery assume that “S” and “Z” refer to Skye and Zara, Tobias’s daughters (and Toby’s sisters). They realize the missing word at the end is “wall” and guess that Toby/Harry has written on his bedroom walls in invisible ink.

Jameson, Avery, and Xander shine a black light on the walls of Toby’s old room and discover that Toby essentially used the walls of his room as a diary.