In March of 2553, CINCONI Margaret Parangosky approved the deployment of an automated remote-probe delivery system, fitted with highly advanced slipspace systems, to Installation 00, the Ark. After the events of late 2552 and the disappearance of John 117, it was decided that reconnaissance should be done on the Ark in order to gather intelligence, recover assets, and establish a secure presence on the structure. The delivery system arrived at the Ark in November 2553 and dispersed its probes. Initial transmissions indicated that the Installation, while damaged, had survived the firing of Installation 08; however, contact with all of the probes was lost soon after this. In response to this turn of events, a manned expedition to the ark was organized. In December of 2553, the state-of-the art UNSC Rubicon was commissioned and dispatched from Luna to discover what had happened to the probes and to continue their original mission. Among its complement the Rubicon included a number of highly-trained remote contact teams; RCT-06 was the designation of one such team.
The Rubicon arrived at the Ark on August 10, 2554. Upon arrival, it detected a non-standard, heterogenic signal eminatig from the structure's surface. After navigating with some difficulty through the debris field surrounding the Ark, the Rubicon deployed all of its RCTs, including RCT-06. Because of the damage to both the structural and environmental systems of the installation, the surface conditions faced by the RCTs were extremely severe. Over the next several days, contact between the Rubicon and the numerous RCTs, the latter having come under attack from the Installation's wildlife and constructs at the behest of the Ark's monitor, 000 Tragic Solitude. On August 18, RCT-06 managed to successfully return to the Rubicon, being the only team to do so. Despite having suffered heavy casualties, RCT-06 had managed to locate and retrieve the source of the mysterious signal, a "severely damaged armature." Investigations by the Rubicon's science detachment discovered that this was in fact the barely functioning remains of 343 Guilty Spark, the former monitor of Installation 04. Over the next several days, technicians extracted data from the construct, during which time it repeatedly breached the ship's firewalls. On August 21, all data extraction was completed and the remains of the monitor were powered down and ejected into space.
Unbeknownst to the crew, however, Guilty Spark had already transferred his consciousness into the Rubicon's computer framework. After subduing the ship's AI Curator, Guilty Spark took control of the Rubicon and forced its crew, including the surviving members of RCT-06, into a deep sleep. Believing after careful consideration that the Librarian was still alive, Guilty Spark then directed the Rubicon to where he believed her to be. The UNSC, having lost all contact with the Rubicon, dispatched search-and-rescue teams, but these could not discover any traces of the ship. The Rubicon was formally declared lost on July 2, 2557 and its complement, including RCT-06, was presumed dead. In reality, the Rubicon crashed into Geranos-a in 2554 after its hijacking by Spark who survived by transferring himself into an armiger salvaged by the crew. The entire crew of the Rubicon, including RCT-06, perished in the crash. Spark buried the crew in a mass grave near the crash site which was discovered three years later in 2557 by the Ace of Spades who had hacked a distress signal ONI had intercepted from Spark.