Discern lies

Discern lies, also known as detect lie, was a divination spell that reveals deliberate falsehoods.

Effect
Each round, you concentrate on one subject, who must be in range. You know if the subject deliberately and knowingly speaks a lie by discerning disturbances in her aura caused by lying. The spell does not reveal the truth, uncover unintentional inaccuracies, or necessarily reveal evasions. Each round, you may concentrate on a different subject.

The reversed form, undetectable lie, protected against magical detection of lies spoken by the target for 24 hours.