In May 2311 the USS Enterprise-B returned to Starbase 77, three months after the Tomed Incident and one month after the subsequent signing of the Treaty of Algeron. With the withdrawal of the Romulans from galactic affairs as a result of the treaty and the avoidance of full-scale interstellar war, a more peaceful and hopeful outlook began to reassert itself over Starfleet and the Federation. As such, on her arrival at Starbase 77 the Enterprise was scheduled to undergo three days of refitting to install special scientific equipment for the ship's first non-military mission in a long time. Her new exploratory mission would launch from Starbase 77 and would take them towards the Röntgen Wall, an unexplained cosmological anomaly.