While you are protected by this spell, anyone using magic to determine your alignment or detect your surface thoughts must make a Will save against this spell's DC, however, when determining the spell's save DC, double your relevant casting ability modifier. For example, mask of virtue cast by a wizard with 17 Intelligence would have a DC of 10 + 3 (the spell level) + 6 (2 x the caster's Intelligence bonus).
On a successful save, the caster knows your true alignment or surface thoughts or both. Otherwise he detects false information that you project, unaware of their false nature. The DM should make the saving throw in secret.
Focus: The holy symbol of your deity. If you are not a divine caster, the holy symbol of any deity may serve as your focus.