The Bynar siblings were employed as engineers and technical specialists. The pair made assisted with making a number of modifications to the SS Snipe, well beyond what was legal for a civilian freighter.
The pair remained loyal to Lieutenant Colonel Jan Kincade after fellow Active Four members Tom Riker, Nog, and Tuvok found proof that Kincade murdered an unarmed prisoner and subsequently decided to oppose Kincade. They locked the medic Khob in the ship's infirmary and disabled several systems, including the transporter.
One-One and Zero-Zero remained on the Snipe when the Elloran Sahde forced helm officer Yal Ixxen to life off. They both died when the Snipe was destroyed by Klingons loyal to Chancellor Martok. (ST - The Fall novel: The Poisoned Chalice)