The Surgeon's Perfect Judgment
A surgeon took one look at a severely injured patient and said, 'No need to treat him.' The nurses nodded in satisfaction and sent the patient away without ever putting him to bed. What happened?

The AI master serves one strange story, and only one. All you may do is ask questions that can be answered "yes" or "no". The fewer questions it takes you to reach the truth, the higher your name goes in the rankings.
Changes every midnight (JST) - one try per night
A surgeon took one look at a severely injured patient and said, 'No need to treat him.' The nurses nodded in satisfaction and sent the patient away without ever putting him to bed. What happened?
Whoever stands behind the counter changes how the answers sound. The truth stays the same.

"Mm, no. ...But you brushed against something close."
Calm and grown-up, and now and then she teases your reasoning to see if it wobbles.

"...Yes."
Hardly says a word. Only when you touch the heart of it does his voice soften.

"Ho ho, that's not it. The sea is wide, you know."
Slow, cheerful old-timer talk. The further off track the question, the more he enjoys it.
The master serves a short story where something doesn't add up. What happened, and why? That is tonight's mystery.
You may only ask questions that can be answered "yes" or "no". When you touch on something that matters, a "fact uncovered" is written on the order slip, one by one.
When you think you have it, tell the truth in your own words. The master checks whether you covered the key points; a miss adds one question.