The first part of the Schattenkrieg trilogy which, however, was not continued beyond its first part so far. The story does not properly conclude, and ends with a "To be continued" note. En Passant is also named the 5th book in the Das Goldene Zeitalter cycle, the 2nd book in the Great Game cycle, and the 15th in FanPro's line of Classic BattleTech Novels.

The First Prince of the Federated Suns is dead, and it's Susan McEvedy's fault. Together with her assistant Collin Redburn she leaves no stone unturned to find the perpetrators of the assassination, and resorts to increasingly ruthless means. Tetsuo Yatomo is the new right hand of the Coordinator. But his new position comes with many powerful enemies, including the director of the draconis secret service ISF. Neither of them is aware that they are crucial figures in a net of intrigue and politics, and that it will depend on their decisions whether the fragile peace of the Star League can be maintained, or if the Inner Sphere will be swept by war anew. First part of the Schattenkrieg trilogy.