The Mystery of the Keys Event 2023 commemorated the end of the Official Recode's early release stage, beginning on 22nd September 2023, and ending on 13th October 2023. The event ran for 3 weeks, and featured the first-time release of UGC items obtainable directly from the game itself. It was also the first event where, in order to obtain the next core part mission set, it is required to complete all of the previous core part tasks. Core missions are those which involved the UGC prizes directly from completing their quests. If a UGC limited item runs out, an alternative prize is given instead. Side missions usually gave a lower prize and do not require previous quests to be completed (excluding the Help Rebus side mission).
Alongside the new event was the recode's importing of legacy game progress and the recode's new features, as well as a new Plushie being added: Smore Cat, which was obtainable through a code during limited-time events and giveaways in the official CoS Discord and Erythia's Twitch. Additionally, Reviiaton received a new redesign, Ripirin was introduced into the game as the first Death Gacha creature, and Altulis was released as a 
Robux creature.
Although Sonarian Font had already been used sometime before, this was the first event where Sonarian Font became not only the key for reading some Lore hints, but a vital asset for important quests. This especially applies to some minigame parts, as translation of the Sonarian Alphabet is often mandatory to decipher clues.
Part 1[]
Part 1 began on September 22nd. It unlocked both the Boreal Warden's core mission and the Mysterious Clues side mission.
Boreal's Quest[]
- Main Prize: Boreal Warden's Key (first 5000 global completions).
- Alternative Prize: Ice Material Override.
- Quests:
- Experience the Winter Season 5 times. This was later changed so that the player only needed to experience the Winter Season 3 times.
- Survive the Tundra Biome for 30 minutes.
- Find all 5 Ancient Key Fragments (Boreal ones).
- Use the correct spell to bind the ancient key.
Spell minigame[]
The Spell minigame is a small minigame initiated upon interaction with the Spell Book; consisting of completing the correct pattern match according to a spell guide shared through the Official Discord and leaked on several secondary Discord and Wiki guides, with the following image being one of them. Once the correct Spell has been cast, it becomes impossible to interact with it again.
For each rune, along with its respective name and element, there is a different book.
The spell guide indicates that, at least for part 1, the translation of the 8 symbols lower set are, from top-to-bottom and left to right:
Marivox - Acid (First) // Nivalith - Aqua (Second) // Velorise - Storm (Third) // Zephyrion - Light (Fourth)
Hiraeth - Air (Fifth) // Enchantia - Dark (Sixth) // Ethereve - Ice (Seventh) // Fyrithm - Fire (Eighth)
Additionally, 1st claw mark - Air; and 2nd claw mark - Fire
Mysterious Clues[]
Mysterious Clues is a side mission which rewards players with a copy of the Nebula Color Palette upon completion of the following three missions:
- Experience the Mythic Season 5 times.
- Experience the Warden's Nebula Event.
- Discover 4 clues hidden around the world.
Cooldown: 60 minutes (1 hour).
As a secondary reward, the messages on the Mysterious Clues offer some codes.
While this mission can be done in theory multiple times, durings parts 1 and 2 it was impossible to redo again, as the 4 hidden clues stopped being interactive after being found, and during part 3 a bug could case some of them to not be intractive as well.
Part 2[]
Part 2 began on September 29th, and unlocked the Eigion Warden's core mission. Unlike the other missions beforehand (both core mission and side mission), two of the quests were locked on purpose for 24 and 32 hours with the purpose of discouraging players from pulling all-nighters the first night to get the UGC item or to complete the Quest.
Eigion's Quest[]
- Main Prize: Eigion Warden's Key (first 5,000 global completions).
- Alternative Prize: Eigion's Follower Signature Look.
- Quests:
- Complete the Boreal's Key Quest.
- Collect 20 of Eigion's Pearls.
- Unlock the color memory door.
- Hatch 25 players as an Aquatic creature.
- Unlock the key's number combination.
Eigion's Pearl Delivery Minigame[]
Pearl aspect in-game. Notice the pink glow
The Eigion's Pearl Delivery Minigame consists on finding 20 small pink-glowing pearl scattered across ~30 fixed spawns on the map, and deliver them one-by-one to the Pearl Reception area located inside the Eigion's Warden Shrine. The reception zone could potentially be interacted from the roof, making entrance to the shrine unnecessary.
Please take into account that during the first week only 1 pearl spawned (now they are 5) for the entire map until collected, and can appear anywhere between the varied spawn points. This can result in the quest being somewhat lengthy depending on where the pearls spawn. Additionally, all pearls spawned are client side and are unable to be collected or seen by other players. It is recommended to look up from a higer ground/visible area to do rapid checkups, and to not overexert yourself. Take your time, and enjoy the game meanwhile.
Locations on the delivery dropoff and the pearls can be seen on the Recode Main Map, also accesible through the Main World (Sonaria) page.
Key Numbers Minigame[]
The key numbers minigame for Eigion's Quest is a multiple step puzzle that requires use of a Sonarian Alphabet cipher.
The first step is to unlock the color memory door via accessing it from the portal. If Boreal's Quest was not completed, a barrier will be present in front of the door and thus prevent access. The memory color door can be unlocked by repeating the pattern the game previously repeats and momentarily becomes longer, like a "Simon Says" game, but with a twist: none of the first column from the left options are considered correct directly:
- If it tells you to press the paw, press the diamond.
- If it tells you to press the claw, press the leaf.
- If it tells you to press the fire, press the feather.
Once this is done, the door will be unlocked, and there will be another room in which the Eigion's Key can be seen chained atop an altar. To free the Key the correct numbers must be entered in the provided six slots (more than one digit can be entered per slot). Incorrect attempts will force the player into a five minute cooldown, and the numbers required to unlock the Key will then be randomized again.
There are 12 tablets scattered across the map, in pairs. For each pair:
- One tablet contains the numbers used for the key. These numbers are random and personal for every player. Originally they went from 1 to 99, but after week 3 the range was changed from 1 to 10.
- The other tablet in the pair contains a hint in Sonarian codification of a Roman numerals (which only use I, V, X, C and M, making them easier to remember when performing the translation), which will never change and is not personal. This hint is towards which order the numbers must be entered in.
Part 3[]
Part 3 began on October 6th. It unlocked the Angelic Warden's core mission, along with the Help Rebus missions.
Angelic's Quest[]
- Main Prize: Angelic Warden's Key (first 5,000 global completions).
- Alternative Prize: x2 Revive Tokens.
- Quests:
- Complete the Eigion's Key Quest.
- Beat the Angelic Warden's obstacle course.
- Discover all of the Warden shrines.
- Grow 300,000 creatures to 100 age as a community.
Angelic Warden's obstacle course[]
This minigame consists on reaching the finish line at the end of an obby. This obby has specific checkpoints which can be interacted with to save progress, as well as several effects which will reduce hunger and thirst depletion by 25%, increases growth speed by 9900%, disables damage and gives a 100% extra stamina regeneration. Additionally, only strafing and Jump will work: nesting and using any active ability from the normal active ability buttons (including Ambush, Grab and Latch) have been disabled. Dart may not be disabled, but since the environment lacks any water, it will not work at all, either.
The area contains multiple obstacle courses: at first a simple jump section, which gets more complex the more you advance, with an invisible-wall labyrinth mid-way and some invisible platforms later on. Getting out of bounds due to a fall will return you to the nearest saved checkpoint. Checkpoints are kept when leaving to eat or drink outside.
To reach this area, it is required to reach a specific teleporter in Redwoods. It is required that the creature used can jump, and not a flier/glider/semi-aquatic with the ability to glide, since those are not allowed. It can give access to the obby to creatures without enough jump power, since some sections of the obby do not require jumps to be passed.
Help Rebus[]
Help Rebus is a side mission that rewards players with one Urzuk Species upon completion of these following missions:
- Complete Angelic Warden's Quest (and, by extension, complete the Eigion and Boreal's Quests).
- Collect and deliver 10 of Rebus' notes.
- Discover Rebus' notebook.
- Experience 5 disasters.
While Rebus' notes can be found and delivered to the mountains dropoff point by any creature and sometimes you may find more than 1 at a time, Rebus' notebook seems to be restricted to been seen by some creature and season restrictions, apparently with only Pero and Ikoran being capable of seeing it, and possibly only during Spring/Summer/Drought at night.
Locations on the notebook and several notes can be seen on the Recode Main Map, also accesible through the Main World (Sonaria) page.
Trivia[]
- During the first day of the event, some interesting event-related hiccups happened:
- Some unknown additional Ancient Key Fragments were found which did not count at all for Boreal's quest. These were originally suspected to be for Eigion Warden's quest, although this is now confirmed to be false after the release of part 2. It is more possible that these locations could be used for the Angelic Warden's or Help Rebus Quests.
- During the first three hours, the entire game was temporarily closed as a private experience.
- After the release of Eigion Warden's mission, some of the quests and minigames were bugged:
- The pearl quest, which was locked at the time, still spawned pearls in older servers due to the bugfix patch not receiving a global server shutdown. This enabled players who remained in said servers to complete the mission earlier than intended, leading to around 10 or so players receiving the key earlier.
- After the release of the Angelic Warden’s mission, one player was able to seemingly exploit the mission to obtain the Angelic Key earlier than intended, leaving everyone else 4,999 keys unfairly.
- Due to the community's response for only having 2 Revive Tokens as alternative Angelic Warden's Key prize, Erythia added an Angelic Signature Palette, which would be available from a 24-hour redeem code when the Halloween Event 2023 began.