Talk to First Sergeant Richard Wolfe and he says:

"We heard about you, but in order to gain our trust you need to do something for me, you see I'm the guy that runs this place."

Respond with "Ok?"

"We sent a scout to check out the cave this morning and we have not heard from him since, do you mind going through the cave and look for some clues of what might have happened to him?"

Respond with "Sure can!"

"The cave lies just outside the camp to the Southwest."

Respond with "Ok, thats cool. I will go."

When you have been through the cave as requested, and return to First Sergeant Richard Wolfe, he says:

"Did you find the scout?"

Respond with "No, I'm afraid that he might have gotten eaten alive up there."

"That's what we feared, there are some evil creatures lurking up there."

Respond with "Sure are. So, am I done now?"

"Not so fast. Now I need you to clear out the dangerous creatures outside the camp; they are getting to (sic) close."

Respond with "Ok, catch you later."

When you return after killing the 100 creatures, First Sergeant Richard Wolfe says:

"Good job. Down by the shore, there are some old barrels. Hopefully a few still contain some oil. Go there and see if you can find any oil and bring it back to me."

Respond with "I'm on it!"

This mission requires you to investigate a cave just outside the camp and return.

Upon returning you are given another task to kill 100 creatures in the Fort Victoria area.

Crazy Fish says

The mission actually asks you to kill 100 of the creatures that are found in the Fort Victoria area. The wording is such that it implies you must kill them around Fort Victoria, but it actually means "kill 100 creatures anywhere on Calypso, as long as they are the types of creatures that you find in the Fort Victoria area". So you can combine this with an Iron Challenge mission and hunt Atrax, Molisk or Armax (in your favourite hunting grounds) as they are all found in the Fort Victoria area.