A 3-mishnah daf. On Hallel and the mitzvah to rejoice - both last for all 8 days. Thee Gemara is careful on its understanding of the biblical text. What is the difference between the first night of Sukkot and the eighth, the night of Shemini Atzeret? Perhaps the rejoicing is that much greater after some time in the moment of simcha. Plus, the mitzvah of dwelling in the sukkah for all of the seven days... How do you establish that you are still in your sukkah until the end of the holiday? Taking grew care to avoid adding to the mitzvah (bal tosif) inappropriately. Also, the final mishnah, on the water libation in the Beit HaMikdash, with details. Followed by a strange Gemara that seems to turn the rejoicing on its head.