With No Warning

The destruction of an unarmed merchant vessel, with no warning, shocked everyone, and Vice Admiral Gale Harkness, is sent to investigate.
What she finds is a single dust cloud that is all that remains of the EV Harmonica.
Then two more ships, but this time of military origin, disappear in the same way, and Humanity, together with their Shi-az-ee allies, prepare for war.
A deserted colony, a mysterious empty building, a strange ion trail, ships that leave no jump signature, and another unwanted promotion, are just some of the problems that Gale has to face before the mystery can be solved.