LitCharts assigns a color and icon to each theme in The Da Vinci Code, which you can use to track the themes throughout the work.
Conspiracies and Secrets
Art and Symbolism
Faith vs. Knowledge
Sacred Femininity and Revisionist History
Power and Manipulation
Summary
Analysis
Having broken into Teabing’s safe, Fache sits alone with the rosewood box. Inside, he finds a stone cylinder whose letter dials spell “SOFIA.” It is empty. The police dispatcher calls: Vernet is repeatedly trying to reach Fache. Fache takes the banker’s call. Vernet confesses to helping Langdon and Sophie escape before realizing they were murderers. He is desperate to retrieve what they stole (despite having a key and password), worried a robbery will sully the bank’s reputation. Fache assures him the item is in good hands.
It's unclear from Fache’s reaction whether the cryptex signifies anything for him (which it would if he were the Teacher). Likewise, if Vernet is the Teacher, he may be trying to obtain the keystone for himself under the pretense of reclaiming a client’s property. By withholding the Teacher’s identity from the reader, the novel increases suspense.