A calming candle from Sneed Galliway in North Qeynos ( 289, -18, -75 ) /waypoint 289, -18, -75 inside Sneed Galliway's Trading Post.
I should find the cave. This is an instanced zone called The Gathering with an entrance/door located near the Wu camp at ( 970, 142, -472 ) /waypoint 970, 142, -472 in The Lesser Faydark.
Wait for the first 3 NPCs to enter the cave and walk to the meditation mats one by one. After all 3 have entered and sat down, a spider will spawn. WAIT until Galabo reacts to the spider, then right click and "shoo" it, chasing it to the cave wall. After this, Merrek will enter the cave and walk to the mats. If you do not wait for Galabo to react, Merrek will not enter and you will have to zone out and back into the zone and start over.