Megillah מגילה

The first chapters are about Purim: when the scroll is read in cities walled from ancient times and when in the rest, who is obliged to read, in what language, and that one who reads it backwards has not fulfilled the commandment.

Then the tractate turns to what proved more consequential: which passages of the Torah are read on festivals and fasts, how many are called up, what may and may not be translated aloud, and what is done with a synagogue that has been sold. From here comes almost the whole shape of today's morning reading.

Order: Moed. There is Gemara in both the Babylonian and the Jerusalem Talmud.