The first area of the Den contains a pair of bandits with a table and a fire- as you approach, they’ll be talking about how uneasy they feel with the Alik’r staying further back in the cavern. If you ambush them, you can take their stuff and climb the ledges beside their table to get into a loot chest and some mushrooms, but you can also sneak by on the far side of the cave with a little difficulty.
The next chunk of cave is a little more difficult to get through unseen, as it’s very well-lit and has two actively patrolling guards. Fortunately, the archer isn’t much, so if you can ambush the melee fighter you’ll be fine. Tumble them for their stuff, grab some salable ale if you like, and dig into the corner where a potion and a satchel rest on a crate. Once you’ve scrummed the room for anything worth the effort, move on to the next area- the most heavily populated room of bandits.
There’s a large ledge overlooking the dining area- an archer waits up here. A second archer paces on the far side of the room, and there are at least two bandits near the dining table at all times. It’s possible, if difficult, to sneak past- but the sheer number of bandits here and the small size of the passage leading to the area makes it amusingly easy to trap them all in a line in the passageway and just keel them over as they come around the bend. Be very wary of the mage, whose ice spells will ruin anyone not a mage themselves, while mage players will have a lot of trouble with the two archers and three to four melee bandits that will jump you at the first opportunity. Ranged attack players need the corridor to keep from getting swamped and attacked by too many enemies at once, though agile melee players may find it amusing to dart around the bandits and make them shoot one another.
Once you’ve finished off the bandits in here, collect what food you like from their dining table and head through the passage to come out on the ledge and swipe the supplies the archer up here was using. Make sure you prod the bear traps in front of the hallway further on rather than stepping on them, it can be quite a ding in your health to get your leg chomped.
The cave here starts getting a bit waterlogged, leading to an area with a wooden ramp up. You’ll find yourself surrounded by seven or eight scimitar-wielding Alik’r, as well as Kematu, who stands right above the entrance you used to get in. Regardless of what you’ve said or done previously, Kematu wants to talk to you before whatever happens. He explains that Saadia betrayed her people and a Redguard city fell because of this, during a war with the Thalmor. According to him, he is here at the behest of the Redguard houses as a whole, to bring her back to face justice. You can choose to end your conversation here by trying to kill him, or you can attempt to talk to him face to face.