Chp. 16 verses 1 - 16: Introduction, begins with after the death of the two sons of Aaron and a warning from Hashem not to enter the Holy of Holies at will. It would only be allowed on Yom Kippur and following the exact ritual that Hashem would describe. Portion continues with a description of the Yom Kippur service that could only be done by the High Priest. Also the ritual of the two goats one to G-d and the other to Azazel.