Trouble with Fighters Guild

[MaximusVortex]

I am having problems completing the objectives for the fighters guild quest "Harlun's Watch".  I have been to speak to the lady about the missing people but when I enter the cave, and stand right on top of where the green arrow says I should be, nothing happens.  All there is on the floor is 2 dead skeletons, 2 dead Zombies, a pile of planks and an empty chest.  A walkthrough says I am supposed to find the body of some dude, but it isnt there.  I am worried that I have been through this cave already just through random exploration and by killing everything inside the cave have destroyed my chances at completing the quest.

Thank you