Nehemiah

The Book of Nehemiah at one time was part of the same book as Ezra, and they both talk about events happening at roughly the same period of time.  Nehemiah was an official in the Persian court, during the time of Artaxerxes, the king who disrupted the re-building of the temple in Jerusalem.  The story of Nehemiah focuses on the rebuilding of the walls that protected the temple and the city.  A group of local people from non-Jewish tribes (Samaritans, Ammonites, Arabs and others) are recorded as trying to stir up trouble to prevent the building of the wall.  Eventually this opposition is thwarted, and the walls are rebuilt.  People confess their sins, and there are many lists of names of people who returned to Israel and helped rebuild the walls.

The book seems to be a kind of covenant for the newly re-established city of Jerusalem, now that the Jews have been given their city back (verse 9:38).  The issue of reform seems to be an important one in the book.  Concern for the poor is another thing that comes up in the book (chap 5).  In many ways it is a similar book to Ezra, so you can see why the two books were put together at one point in time, whether or not they had the same author.