Use the Crystal of Stealth to sneak into the Serra Camp. Remember to use the Serra Teleport Array to enter the camp. Once there, find the Serra Tribe Classic I and take it to Horus.
Tip: after you get the Serra Tribe Classic I, you can use theSerra Teleport Array to leave quickly

Show Quest Info

Introduction

Horus keeps a constant eye on the Serra Camp, but he cannot locate Set's Temple and he has not determined how to destroy its protective totem. You must infiltrate the Serra Camp and find a way to destroy their totem. Get ready to sneak in using the Crystal of Stealth.
Notice: Crystal of Stealth is only effective for 2 minutes.

NPC Dialog

I'll be frank with you, the totem is extremely durable.
When you infiltrate the camp using the Crystal of
Stealth, you will need to look for clues as to how to
destroy it.

Quest Completion

Yes, this does indeed appear to be the Serra Tribe
Classic I. It contains a record of the history of Serra
Tribe. It includes the construction methods for the
totem. It was made out of a giant rock, and then
enchanted by an evil ceremony that went on for a
month and a half! This must be the reason I could
not destroy it!