It's not very difficult to adapt the standard force-net binding spell, and Yfandes can give him suggestions as well as reassurance.

:Go head to your room: she suggests as soon as he's done all the requested magic. :Herald Jores is on top of all the followup here, you did the heavy lifting during the fight so it's only fair you get to rest now: 

: Thanks. I'm really glad Herald Jores is here and knows what he's doing.: And then Abras goes to his room and sleeps the sleep of the adrenaline-crashed. It's an objectively unreasonable bedtime and he's going to ruin his sleep schedule but that is a problem for Tomorrow Abras.

Nobody bothers him before whatever time it is that he wakes up on his own. 

That's going to be inconveniently early in the morning and he's going to deal with it by wandering the town like a confused ghost until it's a reasonable hour to go Truth Spell the prisoners.

Yfandes wakes up at around dawn. :....Chosen? How long have you been up?: 

:Uh, I forget. Not that long?: If he had been doing something he would have a better guess based on how much stuff he got down, but his meandering thoughts could have been half a candlemark or two candlemarks or anywhere in between.

:Well, why don't you go join Herald Jores for breakfast and then you can head over to talk to the prisoners?: 

Oh, right, breakfast, that's a thing that gets done at this time of day. :Okay.: He makes his way back to the inn; it's not far in a straight line.

Herald Jores is there, talking to one of the Guards over tea and porridge. They both glance up at Abras, and Jores gives him a concerned look. "You all right, lad?" 

Oh damn, he looks concerning and doesn't know how to stop. "I'm fine. Just woke up early and went for a walk. Uh, how are you?"

"Doing fine. What a mess we've got here." He makes an irritated sound. "Oh, and did you hear?" 

"Uh, no, probably not; what's the matter?"

"Not the matter, exactly, just a little complicated. Arina was Chosen!" 

"Oh! Uh, good for her? She's had a lot of surprises recently, hasn't she."

"Right?" He shakes his head. "She seems to be taking it in stride, though. Were you planning to get some breakfast? We can go interrogate prisoners after that." 

"Yeah--I can get some bread or something and eat it on the way." Which will be faster and also totally coincidentally get him out of making small talk.

"Sure," Jores says, absently, and turns back to continue his conversation with the Guard. 

Abras gets his breakfast and is done with it by the time they get to the jail.

The jail contains a number of sulky, withdrawn mages, currently with their hands unbound in order to eat breakfast. Half a dozen nervous Guards are watching them very closely. 

Abras can truth spell them again and ask them about their recent activities, their plans, and anything they know about Master Dark. While being on the lookout for misleading technical truths, because that's what he would do if he was captured and truth-spelled by someone hostile and also brave enough to try it.

These mages honestly don't seem nearly as clever as he would try to be in the same circumstances! They answer questions in monosyllables as much as they can get away with, and drag it out and make him ask half a dozen followups, but they don't otherwise seem to be misleading him with partial truths. 

None of them have ever met 'Master Dark'. Their mage-artifacts come from a source they call by that name, but they're not even sure if it's a person or an organization or what. Their orders are to capture children alive and, at intervals, deliver them to an agent north of the Valdemaran border, whose name they don't know and who always hides his face. 

Is the face-hiding person Gifted at all? Does he act like he has some degree of authority or like he's the same level of grunt as they are?

If he's mage-gifted he's never let it on. They think he could be a Mindspeaker, but none of them know how to test for Gifts, and they wouldn't have dared anyway. He acts like he expects he could win a fight with them, but most people who operate in the far north do, there's no rule of law there and appearing weak is asking to be attacked. 

When is their next scheduled meeting to drop off children supposed to be?

They don't have a regular schedule, they just go up there and camp out waiting for him, they don't know how he knows they're there but it's presumably magic of some kind, not necessarily his.