Thomas Jordan, also known as Jinxo, was a human who worked on the construction of all the Babylon stations. He believed he was the sole reason for the fate of the first four, as he left just prior to their destruction or disappearance, a so-called "Babylon Curse." This belief made him stay aboard Babylon 5, even at the risk of his own life.
Thomas Jordan worked on the construction of all the Babylon stations as a Grade 10 zero gravity constructor, a high-skilled profession in great demand in the sector. He took vacations during the construction of the first three stations, Babylon, Babylon 2, and Babylon 3. Just as he departed each, the station exploded due to sabotage. He decided to stay until the end of the construction of Babylon 4, not taking any leave at all, only to see it "dissolve" as he departed the station. He was afraid to leave Babylon 5 because he did not want to see it succumb to the same fate as the previous 4 stations. This earned him his nickname, "Jinxo."
Unfortunately, as there was no need for a zero gravity construction worker, Jinxo ends up becoming a petty thief and indebted to an underworld boss named Deuce. When Deuce asked Jinxo to help him find ways of smuggling things aboard the station, Jinxo turned him down. Deuce responded by demanding his debts be paid with interest, or else he would feed Jinxo to a Na'ka'leen Feeder whom he had disguised as a Vorlon.
Soon afterwards, Jinxo was arrested for the third time (all three incidents involving "gross incompetence"). Upon this arrest, Ombuds Wellington originally sentenced him to be removed from the station and not allowed to return for a period of five years. Jinxo protested, warning the station would surely be destroyed like the others. Watching the trial was a man named Aldous Gajic, who had come to Babylon 5 searching for the Holy Grail (having spent most of his life searching all the known worlds for the Grail). Gajic offered to rehabilitate Jinxo, and the Judge agreed to release him into his custody. Thomas accompanied Gajic as he visited the alien ambassadors to ask about the Grail. However, when they went to visit Ambassador Kosh, Thomas believed him to be the Feeder working for Deuce and fled. Gajic pursued him and they literally ran into Deuce, who was preparing to feed Ombuds Wellington to the Feeder. Thomas managed to escape and alert station security, bringing them to Deuce's lair. The Feeder was killed and the judge rescued, but not before Deuce shot Gajic, fatally wounding him.
With his dying breaths, Gajic moaned that he failed in his quest, but when Thomas offered to continue it in his stead, the elder officially designated him his successor with Jeffrey Sinclair as a witness. Thomas left the station with Gajic's body, confident that his "curse" was over, and now taking up his friend's quest for the grail as his own.