The edge of warning in Asano's tone makes Tonbokiri put back the vial carefully.

"You are right. Could it be... that this is all to distract us from us finding the true stone?" He looks up from the odd apparatus and ingredients, confident in what Asano has said. "The forest is crafty, indeed. Let us continue the search."

And so the search continues. For quite some time.
Eventually even the patient Tonbokiri has to admit that there seems to be nothing to find.

"I am sorry that we did not find anything today, Asano-dono. Perhaps the Stone is harder to see than we first thought. It would not be a quest if it were easy, after all. Let us go home for now, and try again another day."

There was those chemistry things they'd come across, but... he simply cannot imagine how finding the stone and that could be connected.

"I should say the same. Thank you for accompanying me, and for your insight. I don't believe your luck has run out. It shall simply wax fuller tomorrow."

He gives the boy a reassuring clap on the back.