<P> The first series consists of two episodes as a pilot--a single two - part story based on the novel Red Bones by Ann Cleeves . It was broadcast on 10 and 11 March 2013 . Subsequently, a full second series was commissioned by the BBC . Series two contains six episodes, filmed in 2013 and screened in 2014 . It features three two - part stories based on Ann Cleeves' novels Raven Black, Dead Water, and Blue Lightning . Filming began in April 2015 for a third series which began screening in January 2016 . A fourth series was announced by the BBC in July 2016 . The upcoming series will once again contain six parts and began filming in March 2017 . </P> <P> During filming of the various series, the cast and crew usually worked on mainland Scotland, including Glasgow but also in areas with landscape or buildings reminiscent of those on the Shetland Islands such as Kilbarchan (Renfrewshire), Barrhead where Henshall was born and grew up, in Ayr and in Irvine, North Ayrshire . Filming locations on or near Shetland have included Lerwick, the main port of the Shetland Islands and on the NorthLink ferry approaching Lerwick . </P> <Table> <Tr> <Th_colspan="2"> Series </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"> </Td> <Td_colspan="1"> 10 March 2013 (2013 - 03 - 10) </Td> <Td> 11 March 2013 (2013 - 03 - 11) </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 6 </Td> <Td_colspan="1"> 11 March 2014 (2014 - 03 - 11) </Td> <Td> 15 April 2014 (2014 - 04 - 15) </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 6 </Td> <Td_colspan="1"> 15 January 2016 (2016 - 01 - 15) </Td> <Td> 4 March 2016 (2016 - 03 - 04) </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Series </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> </Tr>

How many episodes of shetland series 3 are there