<page_title> The Legend of Korra </page_title> <section_title> Series overview </section_title> <table> <cell> Nickelodeon <col_header> Originally aired </col_header> </cell> <cell> 2 <col_header> Season </col_header> <col_header> Last aired </col_header> </cell> <cell> Book Two: Spirits <col_header> Book </col_header> <col_header> Network </col_header> </cell> <cell> September 13, 2013 <col_header> Originally aired </col_header> </cell> </table>
The second season (Book Two: Spirits) began airing on Nickelodeon on September 13, 2013.