The Jean d'Arc was an observation platform for gravitational and underspace phenomena. At its current location it was watching a confluence of currents in underspace. The currents were poorly understood, and the mathematics to describe them was still being worked out -- painfully slowly in the opinion of the starships and their crews who had to try and navigate them. Being caught by an underspace current could rip a ship into skyscraper-sized chunks and hurl them back into real-space over several million cubic kilometers. The data that the Jean d'Arc was gathering was being locally processed by an AI and then relayed on, via underspace repeater, to the Coriolus hub.
The AI in charge of the Jean d'Arc was very aware that its radio and laser transmissions had been compromised, and was intrigued that no attempt had been made on the underspace repeaters. The saboteur was staying in the maintainance corridors where there were few cameras, and was carrying a fuzzing device to confuse communications. This in turn was helpful as the AI could locate the fuzz to within a hundred feet, and so could track the saboteur even without the help of the cameras. And the saboteur was making no move towards the underspace repeaters or the AI core.
The AI produced a quantum sigh, a tiny ripple in binary data, and woke up a maintanance golem, a human shaped robot with eight arachnoid limbs used for internal repair-work. Golems were normally controlled via radio link but that would be inhibited by the fuzz. The AI downloaded a PI -- a pocket intelligence, an AI small enough to fit inside the golem's limited processing space -- and gave it instructions to kill.
The maintanance corridors of the Jean d'Arc were inky black, no light was needed by the robots that used them. The saboteur sat cross-legged on the floor wearing goggles and unrolling a cloth bundle. The goggles used very low power lasers to directly illuminate what the wearer was looking at, and night-vision technology to amplify the returned light. Wearing them was a little like peering down a long tube to a picture at the other end, and it quickly tired the wearer's eyes. The cloth bundle was a toolkit, the inside surface was velcro-like and held the metal tools silently apart.
The saboteur selected a wand-like rod from the kit, and held it carefully a centimetre or so above the surface of the wall. As he waved it back and forth, force-feedback in the rod indicated the composition of the wall in front of it. The feedback was the same across the saboteur's reach, so he shuffled sideways, not bothering to uncross his legs.
A couple more shuffles and he reached a section of wall where the force-feedback fell off and he knew that he'd reached the crystalline sections of the databanks. Somewhere within this wall was the data-core that had not been flushed when the Jean d'Arc had laser transmitted the message to the Coloratura nine hours ago. All he had to do now was retrieve the core and transmit its content back to the habitat AI -- the Stella du mort -- and he could get off this claustrophobic observation platform.
He replaced the wand in the kit, and his agile fingers ran across the other tools looking for the panel access tools. Then they froze and he stiffened. Something at the far end of this corridor was clattering.
The AI of the Jean d'Arc noted that the maintanance golem was closing in on the fuzz with an element of silicon satisfaction, and used the additional information from the golem as to which corridor to reconsider the saboteur's location. Then it checked through its data banks.
One was not responding.
The AI began a full systems check and purge, more curious than ever as to what the saboteur was up to, and what it had achieved before being noticed.