The four orbiting satellites which tracked mass, radiation, gravitational shear and a hundred other variables through their pyramidal arrangement communicated with each other and with the central nexus beacon, the supercomputer array at the heart of interstellar navigation.

The technology and skills to construct new beacons had been lost in the civil war. Too many important people had died. Too much data had been lost between EMP attacks and good old-fashioned mass-drivers. The beacons had never been attacked. Everyone knew they were too important for military success during the war, and mundane issues like trade when the war was over.

But the existing beacons had been maintained, and they still worked. Hardware changes had been minimal, and only when absolutely essential. Software changes and updates to the code that ran on the nexus beacon which handled the immense data-aggregation and provided ships with their co-ordinates for the jump, were forbidden.

So the old codes were still valid.

Transit codes were issued. The beacon woke up.

The courier drone, alert to an imminent departing portal broadcast a polite request for surrogacy to any ship that could help.

The portal opened, a red and stormy doorway to a new star.

The courier drone sent a second request. This time it was answered.

A beam of white light emerged from the darkness and lanced through the courier. The coherent energy blast utterly vaporised the defenceless drone.

No trace of it would ever be found. No messages would ever be sent.

The warship stowed its weapon, and glided through the portal.

The fleet followed.

Red lightning flared into space and the portal vanished.

 *** END OF PART ONE ***