Bound by Honor — Glynn Stewart

An enemy of newfound strength
A friend gone missing in the night
A threat that can be ignored no more

Brad Madrid, Commodore of the Vikings Mercenary Company, has once again been drawn into the war against the resurgent Cadre. Called into action in battles across the Solar System, from the fogs of Venus to the ice fields of Ceres, he faces deadly enemies at every turn.

In the midst of the chaos, Brad learns that his Agency contact and partner, Kate Falcone, has gone missing before she could deliver the evidence of treason she carried. With millions of lives at stake, finding her cannot be his first priority, but he searches as he goes.

Then an old enemy shares a poisonous gift as they flee from battle: the Cadre doesn't have Kate Falcone. They know who does, however, and the hints they give Brad lead him to the one place he thought he would never make war…