the spell said，
You see the target as though it's dissected and arrayed before you. For the duration, you gain a +2 circumstance bonus on Medicine checks against the target that depend on its organs, but a –2 circumstance penalty on Medicine checks depending on seeing its skin.
When you Cast the Spell, attempt a special Recall Knowledge check using Medicine to spot and discern a vital organ. If you have a Lore skill appropriate to the creature, you can use that skill instead of Medicine. If you succeed, the next time you deal piercing or slashing damage to the target with a Strike or spell, you deal 4d6 additional precision damage. Once on each of your subsequent turns, you can use a single action to attempt the special Recall Knowledge check again. The extra damage isn't cumulative, so making the check more than once before a Strike or spell has no extra benefit.
the spell asks we use a sigle action to attempt the recall knowledge check,and witch's DISCERN SECRETS let we can use a free action to recall knowledge,so can i use free action to attempt the special Recall Knowledge check?
