Chapter 3 - with a new mishnah! (on the bottom of the previous daf) - the anointed kohen who sins unwittingly because of his own erroneous ruling, and then he leaves that standing of anointed kohen before he has brought his atonement offering -- that is, he steps down because of some blemish unrelated to the erroneous ruling... What animal does he bring if he is no longer the anointed kohen? (In fact, there's no change at this time). Note the attention to the structure of the mishnah. And another new mishnah! On the order of stature of the anointed kohen or the king and a sin and sin-offering (is the sin before they achieve the status, for example?). Also, a shift to focus on the king (nasi) and his offering. Plus, a story of Rabban Gamliel traveling with Rabbi Yehoshua, who had brought flour, and using the stars for navigation. Also, a discussion of "asher" and "ashrei," which have dramatically different meanings. With more in the moral/ethical plane - focusing on the intent of the person who sins, but might have intended to fulfill a mitzvah (to wit, see the story of Lot and his daughters).