On Day 2 of 'The Other 48 Days' s2-ep7, we see Eko carving a walking stick of sorts out of a piece of wood. The night before, Eko had killed two of the Others who had come to their camp and taken 3 of the tail end survivors. Throughout the episode, we see Eko doing more elaborate carving work on his stick, including inscribing some words on it.

Eko uses this stick to attack Michael and Sawyer when they arrive on the beach near the tail survivors camp. He uses it as both a walking stick and a defensive weapon while travelling through the jungle with the other survivors to the fuselage survivors camp.

In s2-ep10 'The 23rd Psalm' we finally get a good look at the stick and discover that Eko has carved biblical phrases and passages on it, including 23rd Psalm, a cross, 'Hateth', Revelations:3, Colosians, Titus, and T14, all nods to Eko's pre-island life as a priest.

Although we now know technically what the stick is, we have yet to learn Eko's reasons for creating it.

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