"I'm sure he'll turn up soon enough," you say. "At the moment, we've got more important things to concern ourselves with."
You ride back down the caravan, talking to your tribespeople and making sure everyone is ready to move on as soon as possible. When you return to the head of the column, Vanya still hasn't returned. You spend a few minutes searching the area, but to no avail—Vanya is gone.
The way out of this part of the marsh lies to the north, but there are also paths leading to the east and to the south.