The last in a series of cruel initiation rites by the Stonecutters. It is remarkably similar to Crossing the Desert, The Unblinking Eye, and The Wreck of the Hesperus: in fact, it is exactly the same. The common thread connecting all of them: they involve a blindfolded subject/victim subjected to repeated paddling on the ass with wooden paddles.
Once the subject has passed the ordeal, he takes the final oath and officially becomes a Stonecutter. Massive ingestion of alcohol and playing of ping-pong follow.
Yes, this is a Simpsons reference.