<Tr> <Td_colspan="11"> Celaena returns to her kingdom for numerous confrontations . </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Empire of Storms </Td> <Td> September 6, 2016 </Td> <Td> 195,332 words / 689 pages </Td> <Td> ISBN 9781619636071 </Td> </Tr> <Tr> <Td_colspan="11"> Aelin cashes in all of her debts and must fight the Valg king Erawan . </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Tower of Dawn </Td> <Td> September 5, 2017 </Td> <Td> 208,320 words / 672 pages </Td> <Td> ISBN 9781681195773 </Td> </Tr>

What is the second book in the throne of glass series