Training to become a Marine
Thomas Lasky was born in 2510 to a Colonel mother, Audrey, who was active in the Insurrection. Due to the extent of this civil war, Audrey was hardly around to raise Thomas and his brother Cadmon who lived on Mars. This caused their relationship and interactions to be void of emotion, having an all-business attitude towards her son. This neglect cause Thomas to become very close with his brother, and become close friends with his classmate Petra Janecek.
When he was 15-16 years old, Thomas enlisted as a freshman cadet in Corbulo Academy of Military Science. His brother Cadmon was already active as a ODST and the two frequently sent video-messages to each other. During the spring of Thomas' first year at Corbulo, Cadmon was ambushed and killed in action. This caused Thomas' attitude towards his training to change, he no longer viewed becoming an UNSC Marine to be his goal, and he began slacking off during training. On top of this, Thomas was not allowed to leave the Academy to attend Cadmon's funeral, as his mother deemed it unnecessary since there were no remains.
Thomas' reputation suffered at his constant disregard for the orders of his superiors and displaying a lack of proficient knowledge of infantry tactics; this led him to be relieved of his duty as team leader of Hastati Squad. Thomas' actions towards the rest of the squad caused them to shun him, or cause a verbal altercation. Worse, Thomas' health declined rapidly during the school's mandatory acclimation to cryosleep; he suffered from large blisters and a persistent cough.
Near the end of the schoolyear, the tension among Hastati boiled over when Thomas and Walter were singled out which resulted in disciplinary training for them, and the remainder of Hastati. Frustrated by the verbal and physical harassment Thomas' endured, he assaulted Walter in the mess hall, where their fight was encouraged by the attending senior cadets and underclassmen. Using fighting techniques they had learned at Corbulo, they were only stopped when Colonel Mehaffey intervened. Taking Thomas' aside, she took this opportunity to mentor Thomas, and make him embrace the warrior culture of the UNSC. This inspired him, and he volunteered to lead Hastati just prior to the start of their final combat exercise. This exercise ended successfully, with Thomas' team suffering no 'casualties'. However, when Thomas charged to the enemy's flag, he finally succumbed to his ailing health and collapsed meters away from completing the objective. Examination by Corbulo's medical staff revealed that Thomas' condition was an allergic reaction to the cryo drug cytoprethaline. As cytoprethaline is vital for cryo-sleep to prevent damage to cells, Thomas was judged to be unfit for UNSC service and was to be medically discharged.
Battle of Circinius IV
Humanity was at war, a thus far secret war, but a war nonetheless. Humanity first fought them in the beginning of 2525, but the war was far from over. A little over a year after their first engagement on board a human freighter, the Covenant Empire had reached the Corbulo Academy of Military Science. There was only one person in Corbulo who knew about the Covenant, General Daniel Black, and he had discreetly been increasing the readiness of a combat response. He had established a group of UNSC Marines on the campus, and had UNSC vessels orbiting the planet hosting several ODST squadrons and a Spartan-II squad.
The attack was quick and without warning, and many cadets and trainers alike were killed in the first few minutes. Among those initial killed, was General Black, his command was taken over by Colonel Mehaffey. When she was killed shortly thereafter, there was no clear authority left, and everyone fled to the space elevator in order to escape the alien assault. Recognising the elevator for an important structure, a Covenant corvette shot it down, bringing the structure down partially on top of Corbulo Academy. As many people were either in the space elevator, or were crowded at the foot of it, this single action killed nearly all of the people present on the planet. Only 4 people of the Academy survived: April Orenski, Thomas Lasky, Chyler Silva and Michael Sullivan. Recognising the threat, the remainder of Hastati squad scrambled to the armoury and tried to take weapons. To their horror, the armoury's gun-lockers were locked of, and they had no way of getting their hands on real weapons. When a Covenant Sangheili Zealot arrived in the armoury, the humans thought they were done for. If it were not for the single Spartan-II soldier, the Zealot would have found and killed them. But John-117 was able to dispatch the Zealot without issue.
John-117 had saved the remaining Hastati squad's lives, and armed them by destroying the locks on the armoury's lockers. The Spartan led them outside, where they were promptly assaulted by Kig-Yar Snipers. Despite their lack of real world combat experience, and with great help by the Spartan, Hastati squad was able to take out the Kig-Yar Snipers. Retreating to a safe section on Circinius IV, they mounted General Black's personal Warthog and drove away from the Academy building. They encountered many Covenant forces on their flight, which resulted in their Warthog being incapacitated and Chyler Silva tragically being mortally wounded by a Needler round. On foot in the dark, the remaining humans were assaulted by a Mgalekgolo pair. Using all their remaining ammunition to take out one of the Mgalekgolo, John-117 entered close quarters combat with the remainder, and was able to defeat it with a fragmentation grenade placed under its armour.
With no hostiles in sight, John-117 contacted his teammates Kelly-087 and Fred-104 who came in a D77-TC Pelican dropship and carried the survivors away from the planet. While flying away, they saw that the Covenant had begun to glass the planet. As this was Hastati squad's first time in real combat, they were all visibly shaken and tired. Upon seeing this, Kelly-087 and Fred-104 took of their helmets, something which John-117 refused. Their youth and unnaturally pale appearance was a surprise to the cadets, but when asked they declared their age classified.
The UNSC Infinity
It is unknown what school Thomas attended to when he escaped the Covenant's assault, but we know he played a small role in the Battle of Earth while stationed on Luna. Then-Commander Thomas Lasky commandeered a Banshee and executed several successful attacks on the Covenant attackers, while being under heavy fire. After the Human-Covenant war had ended, Thomas became part of the crew of the new UNSC Infinity, the largest ship the UNSC had ever produced. Still under construction in the Oort cloud, Thomas played host to Jun-A266 and 5 members of the new SPARTAN-IV program. While Thomas was entertaining the guest on S-Deck, the ship was hijacked by Insurrectionists led by Ilsa Zane. The Spartan-IV senior officer Sarah Palmer quickly put on her Mjolnir armour and instructed her Spartans to do the same. Thomas helped the Spartans by disabling the security systems, turning of the cameras and blinding Ilsa. Thomas did his best to help the Spartans, and in the end the Spartans were able to defeat the Insurrectionists.
Being second-in-command of the Infinity, Thomas was present when Fleet Admiral Lord Terrence Hood and ONI director Margaret Parangosky inspected the now completed ship and subsequent trial deployment on Sanghelios.
Passing the inspection, the Infinity was now sent on its maiden voyage, to search for the remaining Halo rings. After the Infinity had located both Installation 03 and Installation 05, the UNSC established research bases there, and to commence with the decommissioning of the superweapons. Infinity was also a part in transporting a massive Forerunner artefact from Installation 03 to Ivanoff Research Station, a move that cost the Infinity 3 months to complete. When a science team examined this artefact, they were accidentally vaporised and left behind glyphs. These glyphs were translated and gave a set of coordinates. When the Infinity went to these coordinates, they discovered the Forerunner Shield World Requiem. Without warning, the planet suddenly scanned Infinity and pulled the ship into its gravity well. Infinity crash landed inside the planet's artificial environment and came under attack by Jul 'Mdama's Covenant and Prometheans, led by the Didact, a surviving Forerunner. Captain Andrew Del Rio dispatched Thomas and Sarah Palmer on recon, believing that the Infinity could provide cover and hold off the attack at the same time. However, they only survived with the timely intervention of the presumed KIA John-117, who drove the Didact off.
During their time on Requiem, Thomas' relationship with John-117 would prove vital to the Spartan's recovery and the outcome of their mission. He demonstrated unwavering trust in the Spartan's judgement, as opposed to Captain Del Rio's scepticism. This trust led to Thomas aiding John-117's escape from the Infinity to oppose the Ur-Didact when Del Rio refused to take action.
When the Infinity returned to UNSC space, FLEETCOM was unhappy to learn that Del Rio left John-117 on Requiem and relieved him of command. Thomas took de facto command of the Infinity and aided John against the Didact as the Forerunner attempted to use the Composer on Earth, targeting the city of New Phoenix. John-117 defeated the Didact and destroyed the Composer with a HAVOK nuke, though he lost his AI Cortana in the process. The Infinity managed to locate John-117 amongst the debris of the Didact's ship and gave him a hero's welcome.
Thomas later found John-117 on an observation deck with a clear view of Earth. He could tell the Spartan was grieving over Cortana's sacrifice and sympathized with him, as he too lost people he cared about. John stated that their duty as soldiers is to protect humanity, whatever the cost. Thomas notes that he thinks that soldiers and humanity are not two different things and insists that soldiers are not machines, just people. He then leaves John-117 alone and promises to have the deck cleared so he can have time to cope.
Thomas was officially given command during his time on Earth, and was given the promotion to Captain. He was given orders to return to Requiem to clear it of all hostile Covenant Remnant and Promethean forces. Once this was accomplished, the UNSC wanted to establish research facilities inside the planet. He was given new Spartan-IV fireteams which would be led by Commander Sarah Palmer, and an on-board training simulation for the Spartans. Arriving at Requiem, the Infinity exited slipspace and subsequently rammed the command ship of the orbiting Covenant fleet. Thomas then ordered for frigates to be deployed and deal with the remaining Covenant fleet and sent Pelicans with the Spartan-IV fireteams to the ground. The Second Battle of Requiem had begun…
Many Spartan fireteams were deployed, all with their separate orders. It was Fireteam Crimson that discovered and claimed a Forerunner artefact, and the artefact was brought to the Infinity. Shortly after arriving on the Infinity, the artefact spontaneously activated, causing a disruption in Infinity's systems, including loss of artificial gravity and of power to the engine, causing the ship to lose its orbit. Sarah Palmer managed to deactivate the artefact with a hard kick, restoring Infinity's systems to normal. The artefact then became stuck to the floor, refusing to react from any further attempts of "physical persuasion". Dr. Henry Glassman attempted to inspect the artefact, only to be accidentally teleported to Requiem by it.
Needing help to investigate what had happened to Glassman, Thomas was forced to summon the war criminal Catherine Halsey. Dealing with outright hostility from Sarah, Catherine began investigating the artefact and came to the conclusion that it was communicating with Infinity's engines (of Forerunner origin) and something on Requiem's surface. While the fighting was still going underway on the surface, Thomas was focussing on helping Catherine in identifying the artefact. While Halsey was in her cell accompanied by Roland, she used an AI override code on Roland to force him to follow her commands, gather everything the UNSC had on the Librarian, and directly contact Jul 'Mdama. Roland told her that John-117 was on the ship, but before Roland could give more answers, he was able to overcome the override and alert security. A disappointed Thomas told Halsey that he has underestimated her long enough and threatens to throw her in a Cryo-chamber.
Before any of this could occur however, a large number of Prometheans started to materialise on board the Infinity. The Promethean closest to Catherine managed to grab her and teleport her away, while the rest attacked but were eventually defeated by the Spartan fireteams present. Reporting what had happened to the new head of ONI Serin Osman, Thomas was given orders to terminate Halsey on sight. Thomas felt morally opposed to the order, believing that soldiers shouldn't act as hitmen; nevertheless, Palmer chose to follow the order so that Thomas wouldn't have to suffer a court martial. Thomas, unable to dissuade her, contacted Fireteam Majestic and ordered them to rescue Halsey. Unfortunately, Jul had already escaped with Halsey.
But that was the least of their worries, as Jul had set Requiem to collide with its sun and ordered his forces to evacuate the planet. Glassman determined from a map recovered by Majestic that there were two artefacts on Requiem similar to the one on the Infinity. Deactivating them would free the ship, enabling them to escape before they plunged into the sun too. Fireteams Majestic and Crimson worked separately to reach and deactivate each device. Though successful, they barely managed to land on the Infinity before the supernova caused by Requiem's collision caught up with them, only narrowly making it to slipspace.
The Infinity made it back to Earth, Thomas and Sarah were requested to debrief at the HIGHCOM Facility Bravo-6 located in Sydney, Australia. During the debriefing, Lord Hood, Serin Osman, and other Admirals informally debriefed Thomas on the 2nd campaign at Requiem. Thomas explained what happened at Requiem, but hesitated to tell Serin Osman why Halsey wasn't assassinated. Before he could answer, Sarah Palmer covered for him by telling Osman that it was her fault for missing the shot, not Thomas'. Back on the Infinity, Lord Hood told Thomas that there's been an escalation in Jiralhanae raiding parties against the Sangheili throughout Joint-occupational zones; as a result, he has arranged for a peace conference between the Arbiter and a Jiralhanae Chieftain on Ealen IV, with Palmer, Fireteam Bailey, and Fireteam Jackknife as security.
When they arrived at Ealen IV, Admiral Hood, Thomas and Kaidon Thel 'Vadam travelled to the surface, each with a military escort, where they rendezvoused with the Jiralhanae Chieftain Lydus. The talk went on for some time, but then the delegates were attacked by Sangheili Rangers and bombarded by Banshee fire. At this point, Thomas had little to do with the fighting, as Sarah Palmer and her Spartans had taken control of the fighting, albeit aided by Thel 'Vadam himself. Each time they were safe for the moment, Thomas tried to contact the Infinity, to no avail. Thomas left under the protection of Spartan-IV Naiya Ray in search of old Covenant communications equipment. They were able to find the communications jamming device, and destroyed it, before they each boarded a Banshee. These events had enraged both the Jiralhanae and Sangheili, and both were starting to fight each other. Thomas managed to convince them that the real threat was neither of them, that they had to focus on finding the people responsible for the attack.
Someone had known about the conference and had passed this information to Jul 'Mdama. The list of names who knew about the conference was very limited, everyone who knew about it was a high-ranking official. This meant that the investigation had to be kept off the books, this is the task Terrence Hood personally gave to Thomas. Partnered with the Spartan-IV Naiya, they had 96 hours to complete this secret investigation. Thomas sought to enlist the help of his childhood friend, the journalist Petra Janecek, although Terrence was uneasy about this decision. After Thomas and Naiya contacted and met Petra, the three went to the Sangheili colony or Karava, where in a bar they met with Petra's contact, a Sangheili named Zef 'Thral. He informed them that the human collaborator was Daniel Clayton. When the trio returned to the Infinity, they learned that in their absence, Daniel Clayton and his men had attack the Infinity, although they were unsuccessful in capturing the ship.
Thomas would be involved in many more conflicts, and would be witness to many more wars. There would be an incident involving Kig-Yar space piracy, near the planet Ven III. This battle would mark the end of the Kig-Yar pirate kingdom as it was utterly devastated following the UNSC Infinity's attacks. He would also be part in the events surrounding the Janus Key, and would unintentionally give UNSC's half of the Janus Key over to Jul 'Mdama's Covenant Remnant. He had given their half to Glassman to use it in his investigation on the planet Aktis IV, but the Pelican that carried Glassman was shot down. After several more engagements, Thomas brought the Infinity back to Earth. There he was caught by surprise when on the next day Infinity received multiple distress signals indicating AIs shutting down everything from Earth to the Outer Colonies. Then suddenly Infinity's bridge lights darkened and Cortana's hologram appeared. Immediately she called a Guardian to near Earth's space, and Thomas ordered for emergency slipspace jump. Infinity managed to escape right before Guardian's EMP attack knocked out the power of every ship, every starfighter, all the orbital defense platforms, and every city on the surface of Earth. Believing Cortana could track them Thomas ordered to continue random jumps and steer clear of major settlements until they find a way to fight her.