Deadly Enterprise by Christopher Hoare

Deadly Enterprise is the middle novel of the five novel series that feature the strong female storm-crow Gisel Matah, a security agent for the castaway Iskanders on the alternate Earth called Gaia.

In this story she is assigned to make contact with the Felgers, a banking and industrialist family conglomerate. The Iskanders look to increase their customer base as well as outsource rare minerals and products to speed their own development. The Felgers are cautious, knowing the contact will bring the Emperor's wrath upon them. Gisel undertakes to escort the young Yohan Felger to Lubitz to further the contact, knowing that Zagdorf, the Emperor's leading spymaster is watching for them. She also notes that Lubitz and the Iskanders are at war and she could be executed as a spy if caught.

Follow these two, the stuffy and inexperienced Yohan and the sharp-tonged expert Gisel, as they travel by sea, by river and on horseback, with enemies at every turn and the conflict that imperils Lubitz waiting for them to make a wrong move.