A Proper Offering - Act 1 Side Quest
Start Location: Megara
Quest Location: Helicos Pass
Objective: Bring the Sacred Olive Branch from Helicos Pass to an NPC in Delphi
Reward: Permanent Increased Resistances
You'll receive this quest from Timon in Megara at the same time as you update your main story quest for Act 1. For this quest all you need to do is pick up the Sacred Olive Branch from Helicos Pass and deliver it to the NPC outfront of the temple in Delphi.
A Proper Offering is one of the few side quests in the game that offers players a permanent reward on each difficulty. On Normal it gives you +5% to a random resist, on Epic it'll give +7% to a random resist and on Legendary it gives you +5% to all resists. In Titan Quest, much like almost every ARPG, getting high resists is extremely important so this is definitely one quest you do not want to skip.
The Sacred Olive Branch itself is guarded by Arachne - Spider Queen. She's a spider boss that will use mostly Poison damage against you and summon spiderlings.
Note: The Spider enemies you fight during this quest can also drop Deathweaver's Legtip which is an extremely good Rogue Monster Infrequent.