Wrath of Empire

The Emperor wants peace between warring Families on rival worlds. His brother sees peace treaties as weakness; he aims to seize the throne and rule by strength. And then there's Chalwen, bodyguard to the Emperor's nine-year-old son, heir to the throne. Chalwen takes professional paranoia to extremes, so when she suspects treachery inside the palace her superiors dismiss her warnings. Then the Emperor is assassinated.
People are angry, looking for a villain, and all evidence points to one of the rival Families. Amid riots and military clashes, the young heir and his ambitious uncle fight for the throne. Chalwen must protect the youngster while solving the Emperor's murder to defuse the conflict. But the uncle has powerful supporters opposing Chalwen's every move. Throw in a deranged arms dealer keen to profit from the chaos, and full scale interstellar war seems unavoidable.