Meepo nods eagerly and hurries accross the narrow ledge along the pit again. Since there's only about five feet of room between the door and the pit, you decide after a few moments to arrange yourselves so that Meepo, Ydyr, and Kuma are by the door, with the others ready to offer ranged support from the other side.
Meepo begins calling out to the other side of the door in draconic, and Heirmund is surprised to hear that he pretty much sticks to the script Jair outlined for him. When he's done, there's silence for a short while--and then something responds.
Any doubts whether there really was a dragon, or whether it was in that next room, are dispelled the moment you hear it speak. Something about the gravelly, rumbling voice reaches down into your ancestral memories and evokes a fight-or-flight response from deep within you. This, even though most of you cannot understand the draconic, and even though something about the voice gives you the impression of great youth. It becomes easier to understand how the kobolds could worship these creatures as gods, if the voice of one young dragon, heard but not understood from the other side of a door, could provoke such a reaction in you...
Heirmund can't make out every word from his position beyond the pit, but he gets most of it: the gist of it seems to be that to prove he's not under duress, and to give more details, Meepo--and Meepo alone--may enter the room to talk with the dragon.