On the 31st, Yumis Longtooth, a Walrus-folk Mage, arrived at Landen's lord's quarters. As soon as he entered the room, he spotted a standard-sized Magic Pattern Cabinet in the hall.
"Duke Landen, please allow me to offer my heartfelt congratulations on your string of victories on White Mountain Island. I must also take my leave. As a Mage of the Sea Beastmen, I have to return to Moonfall Lake as soon as possible and fight alongside my people!"
The moment Yumis saw Landen, he got straight to the point and announced his departure.
"Teacher Yumis, I came here because I went north yesterday. Someone happened to order one of these Magic Pattern Cabinets from a workshop in Night-Kirin City, so I especially wanted you to take a look." Landen pointed at the most conspicuous object in the hall.
"At the customer's request, we installed a cooling Magic Pattern on the outside of the cabinet and a filtering Magic Pattern on the inside. In other words, oxygen will continually be produced inside the cabinet, while the water around it will cool rapidly."
"Hmm, you mean..." A glimmer appeared in the Walrus-folk Mage's eyes.
"This was ordered by someone else, and its construction is basically the same as that of a power cabinet, so it can operate underwater. Keeping it cool and filtering the water for extended periods takes a tremendous amount of magic. Without a Magic Furnace, only a High-Rank Mage could probably operate it. However, once it's left in one place, it will slowly fill with oxygen. In about two hours, it can produce oxygen equal to a quarter of its volume."
"Ah!" Countless ideas raced through Yumis's mind. "Then may I ask roughly how many Gold Coins one of these would cost?"
"About the same as a power cabinet,