In 'Firstborn', Riker contacts Deep Space Nine to find information on the whereabouts of the Duras sisters, who were last seen on the station. (As depicted in the DS9 episode 'Past Prologue'.) However, instead of speaking to someone like Sisko, he speaks to Quark instead. Quark clearly isn't at his bar, and there's a Starfleet officer standing nearby, so I assume Quark and Riker's chat was sanctioned by the senior officers of DS9. But still, the question remains; why him? 'Firstborn' did air in between the DS9 episodes 'The Maquis, Part I' and 'The Maquis, Part II', so it's possible the senior officers were just too busy at the time and authorised Quark to speak on their behalf. This, however, can't be confirmed as neither DS9 episode has a stardate. Even if they're assumed to take place at the same time as Firstborn, I find it hard to believe that any official duties would be delegated to Quark. Why not Odo or someone like that? Is there anything I'm missing or is this simply the best explanation?