<P> The music was composed by Ramin Djawadi, who previously scored del Toro's 2013 film Pacific Rim . </P> <P> The original key art for the series prominently featured a worm, a vector of the vampiric virus, burrowing into a person's eye . Following complaints from members of the public, FX announced that they would replace the artwork on several of their billboards . </P> <Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> </Tr> <Tr> <Th> First aired </Th> <Th> Last aired </Th> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 13 </Td> <Td_colspan="1"> July 13, 2014 (2014 - 07 - 13) </Td> <Td> October 5, 2014 (2014 - 10 - 05) </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 13 </Td> <Td_colspan="1"> July 12, 2015 (2015 - 07 - 12) </Td> <Td> October 4, 2015 (2015 - 10 - 04) </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 10 </Td> <Td_colspan="1"> August 28, 2016 (2016 - 08 - 28) </Td> <Td> October 30, 2016 (2016 - 10 - 30) </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 10 </Td> <Td_colspan="1"> July 16, 2017 (2017 - 07 - 16) </Td> <Td> September 17, 2017 (2017 - 09 - 17) </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> </Tr>

How many episodes will the strain season 4 have