Out of Darkness

I cut yesterday's offering short because it felt like the whole idea was getting glossed over, and I wanted to reproach it. As I set out yesterday, this is a multipart encounter that really fits over several days in terms of this presentation. What I was putting out there yesterday was meant as an overview of the whole scenario.
The first part isn't as critical for details. I think you just pick a gang and keep sending in the troops... I like using kobolds. I'd send in a band of 10-12 kobolds with 2-3 ogres and 5-6 winged kobolds. The ogres should be able to pin the characters down in order to give the kobolds advantage. The winged kobolds can zip in and out, staying out of melee range. From there, just pour more in to overwhelm them. I like the twist of having Ference connected with the attack. I'm not sure how it could have been prearranged, but its possible they were watching him and followed them into the canyon, gathering more forces to capture them. It is a good way to get him out of the picture, maybe to bring back later as an enemy.

Once the party is taken prisoner, they are bound and gagged, their wounds stabilized, and they are transported to the kobold warren deeper in the mountains. They awake after a long rest in the orange shaded area of the map accompanying. They could all be in one larger room, or separated into the smaller rooms. They away in darkness, with many of their belongings missing.
Fortunately for them, the kobolds have mostly evacuated these tunnels to attend a larger gathering deeper into the hills. They have left a very sparse number of guards. There is a main group at the entrance to the tunnels, indicated by the blue oval. This section of the tunnel is elevated from the remainder of the labyrinth, with ladders withdrawn to the upper shelf near the exit.
Because of this, there are few kobolds scattered throughout the complex. There is a guard room off the main tunnel either way out from the shaded area where the prisoners awake. The one to the right has 3 kobolds and the balance of the party's gear. The other has 5 guards. None of the guards is really expecting any action. They believe the party is too ill and injured to act, and are content to let the darkness keep them safe. Leaving them stripped down and alone in the dark with guards in either direction gives them confidence in their safety.
The key here is to encourage the players to figure out their situation and work out a means of escape. This isn't meant to kill or destroy the players, or to keep them prisoners, just to have some fun with managing their escape and recovering their belongings. It also serves as a way (mentioned above, of separating Ference from them with something to hold against him in future).