The waterside barbecue has become the burial ground for four young people. A top botanist and his girlfriend are found lying on the ground with two of their primary school classmates. It looks like they have died of poisoning from eating undercooked meat, although the polluted water in the stream is also a possibility. More suspicious is an open bottle of tea next to them, which is revealed through analysis to contain traces of hemlock, rarely seen in Taiwan. During the investigation, a botany article by the deceased is published in a famous journal. Could it be that an assistant professor in his department who liked his girlfriend killed him out of jealousy of his success, or was it that he made a fatal mistake in his research?