Related to the long black library post, near the end it mentions a new AOS trilogy pend by Nick Horth, found some new info, Called Callis and Toll: Silvershard extending the story of characters from City of Secrets. Found a blurb at http://www.hugendubel.de/de/buch/nick_horth-warhammer_age_of_sigmar_callis_und_tol-30496965-produkt-details.html (translated)
"Witch hunter Hanniver Toll and former release soldier Armand Callis are following Ortam Vermyre, the treacherous judge of the city of Excelsis. Together with dangerous corsair queen Arika Zenthe and ace fish treasure hunter Shev Arclis, they must brave the dangerous waters and jungles of the Claw Coast to stop Vermyre before he reaches the lost city of Xoantica. In their forgotten ruins lies the silver shard, an artifact from another world with the power to change reality itself. If she falls into the hands of the arch-traitor, the fate of Excelsis and perhaps even all of the great Sigmar towns in Ghur - the realm of the beasts - is at stake"