Key of Aries
Spoilers Ahead
This page contains spoilers for a lategame puzzle reward. View at your own discretion.
Key of Aries is a special item in Blue Prince.
How to obtain
The Key of Aries is obtained as the prize of the puzzle in The Precipice/Unknown. Once the correct combination is placed into the clock, a compartment with the key opens. The clock does not remain open between days.
Usage
Although it is a key, its usage is unclear; it cannot be used on ordinary locked doors in the special key menu.
Spoilers Within
This section contains spoilers for using this item.
Puzzle solution
The Key of Aries is used on the box in the Treasure Trove when it is drafted on the Grounds using the Blessing of the Monk. When this is done, the treasure trove contains a black box with the same color scheme and insignia. Using the Key of Aries on the box provides the Royal Scepter, and permanently adds the scepter as an item in the Treasure Trove if not already owned.
Additional information
The Key of Aries is mentioned on one of the notes in The Precipice/Unknown: "THE BLACK KEY IS LYING WITH THE LAST KING OF EIGHT". This implies that that puzzle does actually lead to this key, implying its existence (and perhaps connection to the usage) even before the item is obtained.