Prior to 2369, Leck undertook a mission in Cardassian territory which took him to Terok Nor. After eliminating his target, Leck met Quark and spent some time in the bar. Leck found that Quark had a Deltan holosuite program that he had been trying to find for years.
In 2373, Leck had a mission to Earth to eliminate a Federation official who was promoting a trade agreement that was detrimental to Ferengi business interests (DS9 - novella: The Elimination of Latinum: The Story of Leck)
In 2374, Leck was recruited by Quark to join a team of Ferengi commandos that were trying to rescue Quark's mother Ishka from the Dominion, who held her captive on Empok Nor. Leck eagerly joined for the opportunity to test his skills against the Jem'Hadar. However, although he claimed he had no interest in gold-pressed latinum, he also hated being cheated—as Quark tried to do by telling the team that there was only a 20-bar reward, when in fact Zek had promised 50 bars to the team.
Later that year, Rom tried to contact Leck after he was unable to reach Ishka, anyone at the Tower of Commerce, or Gaila. Like the others, Rom was unable to reach Leck due to the communications blackout. (DS9 episode: "Profit and Lace")
In late 2376, Leck was hired to break into the Glat Archive and find evidence that the marriage contract between Grand Nagus Rom and Prinadora had not been dissolved. The mission was extremely difficult for Leck, but also a great challenge. Leck managed to infiltrate the facility posing as Torf and downloaded the marriage contract. (DS9 - Worlds of Deep Space Nine novella: Ferenginar: Satisfaction is Not Guaranteed)