<P> The following release dates are the Australian release dates, and may or may not represent the release dates for all of region 4 . </P> <Table> <Tr> <Th> Volume </Th> <Th_colspan="3"> Book 1: Water </Th> <Th_colspan="3"> Book 2: Earth </Th> <Th_colspan="3"> Book 3: Fire </Th> </Tr> <Tr> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> </Tr> <Tr> <Th> </Th> <Td> March 15, 2007 </Td> <Td> </Td> <Td> </Td> <Td> June 4, 2009 </Td> <Td> </Td> <Td> 5 </Td> <Td> June 3, 2010 </Td> <Td> </Td> <Td> 5 </Td> </Tr> <Tr> <Th> </Th> <Td> July 5, 2007 </Td> <Td> </Td> <Td> </Td> <Td> August 4, 2009 </Td> <Td> </Td> <Td> 5 </Td> <Td> September 23, 2010 </Td> <Td> </Td> <Td> 5 </Td> </Tr> <Tr> <Th> </Th> <Td> March 13, 2008 </Td> <Td> </Td> <Td> </Td> <Td> October 29, 2009 </Td> <Td> </Td> <Td> 5 </Td> <Td> October 7, 2010 </Td> <Td> </Td> <Td> 5 </Td> </Tr> <Tr> <Th> </Th> <Td> June 19, 2008 </Td> <Td> </Td> <Td> </Td> <Td> March 31, 2010 </Td> <Td> </Td> <Td> 5 </Td> <Td> November 4, 2010 </Td> <Td> </Td> <Td> 6 </Td> </Tr> <Tr> <Th> 5 </Th> <Td> March 5, 2009 </Td> <Td> </Td> <Td> </Td> <Td_colspan="3"> There is no volume five DVD for this season . </Td> <Td_colspan="3"> There is no volume five DVD for this season . </Td> </Tr> <Tr> <Th> Box set </Th> <Td> June 4, 2009 </Td> <Td> 5 </Td> <Td> 20 </Td> <Td> September 9, 2010 </Td> <Td> </Td> <Td> 20 </Td> <Td> December 2, 2010 </Td> <Td> </Td> <Td> 21 </Td> </Tr> </Table> <Tr> <Th> Volume </Th> <Th_colspan="3"> Book 1: Water </Th> <Th_colspan="3"> Book 2: Earth </Th> <Th_colspan="3"> Book 3: Fire </Th> </Tr> <Tr> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> <Th> Released </Th> <Th> Discs </Th> <Th> Episodes </Th> </Tr>

Avatar the last airbender season 4 episode 21