4-LOM was one of the extremely few droids to take to bounty hunting. He was assigned to a luxury liner, but found it undemanding and boring. He was shocked at how little the passengers seemed to care for their things, and began stealing items to "keep safe". One such item was the Ankarres Saphire, a large jewel supposedly with strong healing properties. His programming began to become corrupted, but no one suspected the thief to be a droid. His life of crime had begun.
4-LOM eventually set out as a bounty hunter, working often for Jabba The Hutt and also frequently being pared for Gand bounty hunter Zuckuss. The pair worked well together, and began working only as a team. On one hunt, their quarry was able to rip Zuckuss's ammonia breathing helmet off his head. The three short breaths of oxygen he reflexively took proved to shred his lungs beyond repair. He and 4-LOM began having to take on more dangerous or risky jobs for higher pay, as cloning lungs was an incredibly expensive process. One such job was capturing Imperial Governor Nardix for the Rebel Alliance.
And shortly after is when they were summoned to meet with Darth Vader aboard his flagship, the Executor. Unsure if it was a death sentence they were walking into because of their job for the Rebels, Zuckuss practiced meditating in order to tap into the Gand talent for intuition. 4-LOM realized that to be a better team, he too should learn intuition. And after that, perhaps even the Jedi abilities linked to the Force.
When Zuckuss realized Vader did know about Nardix, but didn't care, they went ahead with the meeting. Jumping out of Hyperspace though, they found themselves in the middle of a small space battle. The Rebels were fleeing the ice planet Hoth, with cover fire from an Ion cannon on the surface. To win some favor with the Empire, Zuckuss took out the engines on one of the escaping transports. They made sure the Empire was aware of who had done it, and then docked in the landing bay of the flagship.
Standing among the other bounty hunters, 4-LOM watched his partner in fear of any signs of weakness. Zuckuss had injected himself with pain killers, and could not falter in front of the others or the Imperials. After leaving the meeting, 4-LOM was actually able to practice intuition. He wrote it off as illogical, but came to realize that he had to ignore logic to be successful with this. He realized where the Rebels were running to, but in order to show up there without raising suspicion, they planned to capture some of the passengers of the transport they shot down. Once they convinced those on board that they were there to rescue, 4-LOM began calling out the names of the agents with the largest bounties. They would meet at the Rebel rendevous, capture Solo, and bring them all back to the Empire. This would surely pay for Zuckuss's new lungs.Toryn Farr, a young Rebel officer, argued that she wanted the entire ship rescued. If they were to flush out the ammonia on Zuckuss's ship, the Mist Hunter, they could fill it with oxygen and escape with everyone. In order to just get out of there quickly, the bounty hunters agreed. Wearing his breathing suit constantly though only quickened Zuckuss's lung deterioration. And on top of that, when he learned of 4-LOM's attempts at intuition, the Gand assumed incorrectly that the droid was preparing for his departure.After giving in to Farr once more and dropping the wounded off at a base on Darlyn Boda, 4-LOM tried to assist his friend by letting Zuckuss sleep with the healing jewel, the Ankarres Saphire. Zuckuss's condition was dire once they reached the rendevous point. Not only that, but they learned that Boba Fett had captured Solo already. They'd also effectively rescued an entire transport's worth of Rebels, and accidentally joined the Rebellion. 4-LOM concluded that if they could capture Luke Skywalker and Leia Organa and turn them over to Vader, it may well make up for all they've done. But Zuckuss wasn't having it. The Rebels were preparing to replace his lungs, and he foresaw that it would only be the two bumbling droids, C-3PO and R2-D2 that would be captured. It wouldn't be enough, and their deathmarks would remain. It was better to stay. They had a home, and people who accepted and cared for them. 4-LOM came to agree. And in time, his own practices of intuition showed him that when the New Republic came about, and the New Jedi Order was constructed, he would be its first droid member.