While exploring the camp you'll find a worker named Ghorim mashing ingredients. He says Marlok was meant to replace him, but instead is napping over by the weed store. Head on over there. Talk to Marlok and when all options have been exhausted you'll have to get physical. Beat him up (drop your Ore first if you think he's too tough for you), grab his weapon and loot his body. When he gets up again demand he go and help.
Now wait for Marlok to return. You can follow him back if you wish, but if you follow too closely he may fall off ladders or edges and die. Once he's safely back Baal Orun will commend you and reward you with an even harder task, collecting The Swampweed Harvest.