The initial GTVA foray into Federation space was a disaster for both sides. Admiral Morian, disoriented by the events of the past few days and the sudden departure of his commanding officer, bungled initial contact with the Renjian so badly that he was almost immediately relieved of command.

GTVA High Command's intention had been to position the 14th Battlegroup throughout Sol and only then demand surrender as additional GTVA forces from the Fourth Fleet poured in through the node. During the time that the 14th had been absent (between the initial transit and its abrupt return several days later), GTVA High Command had moved the waiting Fourth Fleet into a defensive posture, believing that the UEF had destroyed the 14th Battlegroup. The fear was that the Elders, having interrogated GTVA survivors, might be preparing a breakout towards Beta Aquilae. When the 14th reappeared, Command ordered the Orestes to carry out its standing orders immediately - meaning the execution of the plan to disperse throughout Sol, assume bombardment positions above major capitals, and only then request surrender. The GTVA 4th Fleet was ordered to scramble to the Sol node in Delta Serpentis and begin a crash transit.

Admiral Morian, meanwhile, was exhausted and agitated after the 14th Battle Group's odyssey into unknown territory. His service in Capella had left the man with a deep-set but largely unrecognized fear of the Shivans, and recent events had exacerbated this phobia. Under pressure, he (incorrectly) assumed that the order to 'execute standing orders' meant that the Orestes should refer to standing timetables for the Sol invasion - and since the invasion had been scheduled to begin days earlier, he immediately commenced hostilities. Popular historians have frequently condemned Morian's actions as unprofessional and rash. But, arguably, Morian made the correct choices based on limited information: in the face of the desertion of his beloved Admiral, and a sudden and shocking return from a veritable nightmare, Morian used the schedules and plans that he was aware of to adapt his actions. In a time of tremendous crisis, Morian fell back on his training.

For the UEF's part, the arrival of the 14th was not unexpected. The Elders had greeted the sighting of GTVA probes with open arms, and in spite of a Fedayeen (the paramilitary black ops unit reporting directly to the Elders, often - and arguably correctly - labeled 'state sponsored terrorists' by the GTVA) report suggesting that the probes were stuffed with sophisticated ELINT gear, prepared no military contingencies for the GTVA's arrival. The widespread assumption was that Earth's lost brethren had achieved a degree of peace and enlightenment similar to that which pervaded Sol (barring certain elements of the Kuiper periphery and the military). The coexistence of Terran and Vasudan technological elements in the probes scanned by the Fedayeen was cited as evidence for this view.

Only when the newcomers failed to arrive in a timely manner did the Fleet Admirals (Calder, Byrne, and Netreba) convince the Council of Elders to prepare a limited military response. Admiral Calder also initiated a 'training exercise' for the Third Fleet, loading several frigate divisions with live ammunition and practicing quick-response jumps to various points in the system. When the 14th finally did arrive, the Renjian responded to reports of a massive subspace transit with conflicting orders. The Elders' standing request was that the visitors be escorted directly to Earth. Admiral Calder privately requested that Captain Leicester hold the newcomers at the node as a measure of caution.

When it became apparent that the newcomers had hostile intentions, Captain Leicester reacted rashly. Believing the GTVA warships comparably armed to his own Karuna, Leicester engaged the Orestes while calling for the 3rd Fleet to respond. He promptly found his ship gutted by the Orestes' plasma beams - the first occurrence of a tactical nightmare that would plague the UEF for the rest of the war.

Calder deployed four frigates to the node but wisely held back his destroyer, the Toutatis. The loss of a second frigate to beam fire from the Orestes convinced Calder to avoid committing the rest of his assets, and his ships retreated, leaving the node uncontested. Meanwhile, the Council of Elders had gathered for an emergency meeting and authorized unlimited defensive action by the military. In retrospect, if the UEF had attacked at this point, victory would have been nearly assured; the Temeraire, Duke, Labouchere, and Miranda were all out of action due to mutiny and other vessels were operating at degraded crew levels.

Failure of the Beachhead and Fourth Fleet Assault

At this time only two hours had passed since the arrival of the Orestes in Sol. Unbeknownst to the UEF, widespread mutiny was underway amidst the 14th Battlegroup. Some ships defected wholesale, command crews intact; others were rendered inoperable by onboard sabotage. Had the UEF pressed its advantage at the moment, they might have captured the node (if only temporarily). However, Calder, Netreba, and Byrne were still trying to deduce the capabilities and motives of their opponents, and most of their warships were still loading up for combat at this time.

Two hours later, the Fourth Fleet began its transit into Sol. The 13th and 16th Battlegroups, under the GTD Meridian and GTD Requiem, consisted largely of Capella-era warships, but their Deimos and Hecate combatants - if lacking in the overwhelming shock power of the newer warships - were an easy match for everything in the UEF arsenal. These ships relieved the remaining warships of the 14th Battlegroup and plans were drawn up to assault Neptune.

Although their available assets included two destroyers and multiple corvettes, these vessels were not committed simultaneously. Both GTVA and UEF military doctrine recognized that a warship in reserve was more powerful than one in the field - capable of jumping in and attacking a committed enemy from a weak direction. Moreover, broad deployment of capital or fighter assets left rear-area targets open to attack, including (in this case) the Delta Serpentis node itself. For this reason, both sides committed no more than six or seven warships to an engagement at one time, a policy that would continue for the remainder of the war.

The 13th's initial assault on Neptune was repelled. While the defending force - two frigates and four cruisers - was annihilated by beam fire, the UEF fighter corps ripped apart the 13th's screen and close-assaulted the GTD Meridian with gunship-mounted weapons, demonstrating the UEF's main advantage over its GTVA counterparts. The Meridian withdrew, losing a Deimos escort in the process (The casualty rate amongst the Aeolus class was low throughout the war, proving the wisdom of the decision to reopen production lines).