Chapter 16 sees Angela Wexler having a bomb blow up in her face. She is taken to the hospital for her injuries. The majority of the chapter has various characters then trying to figure out who the bomber is, and nobody suspects Angela. Near the end of the chapter, Angela's parents visit her in the hospital to check on her and give her some encouraging words. Turtle stays a bit longer to say her thanks for Angela not letting the bomb go off in Turtle's face. Turtle also brought Angela's bag, and Turtle is sure to mention that she didn't go through Angela's notes or clues. Those two things are for sure in the bag. The third item in the bag was "incriminating evidence."
"Here, I brought your tapestry bag; I didn’t look at your notes or clues, honest.” But she had removed the incriminating evidence.
Whatever this evidence is, it points to Angela being the bomber. As Turtle is leaving, she tells her sister that bombing herself was stupid. Sydelle overhears this and therefore now knows Angela's secret too.
“Don’t worry, you’ll still be pretty,” Turtle said. “But, wow, that sure was a dumb thing to do.”
Sydelle Pulaski’s eyes popped open in surprise. Quickly she squeezed them shut and uttered another loud snore. Well, what do you know? Her sweet, saintly partner was the bomber.