Arterial drain

Entry drain is one of the rooms in Aeternis.

Background
An ancient artereal Roman-style drain, which houses heavy machinery once used for milling flour.

Layout
This is a straightforward area, where you arrive after jumping down the hole in the chapel. At one end is a sealed door, with seawater massed behind it. Directly opposite is an opening that leaves into the grain silo, with oil on the ledge. Right in the middle is a ladder and an old milling stone leaning on the side.

This is a puzzle that allows you to get rid of the leo down in the silo. Approach the ledge hugging the left wall, to prevent yourself from sliding into the silo (where you are likely to be eaten by a grue). Pick up the pin, hightail it back to the ladder. Go up, where remnants of the mill are. Use the pin in the hole next to the pulley system (in the protruding piece of stone). Then use it to winch the stone up.

The go down and push the stone along. Taking several hundred pounds of rock to the head kills the leo.

Items

 * Pin: Near the edge, watch for the oil slick.
 * Flour: The bag is in the mill up the ladder. Pick it up, it's mandatory.