Truth
Source: Ultimate Intrigue, p. 19
A creature injected with a truth serum must succeed at a Will save or be compelled to answer the interrogator’s questions truthfully. The interrogator can ask one question per 2 alchemist levels (minimum 1). Answers might be brief, cryptic, or repetitive, especially if the injected creature is unfriendly, but they aren’t false. If a creature has been subjected to a truth serum within the past week, whether it succeeded at or failed its save, any new serum fails.