Revita: The Ticking Tower Top Door Guide

This guide will show you content after shard 5

it is highly recommendet to at least beat shard 5 before reading this!

if you want to figure the secret out on your own, why did you click on this guide…?

The first step of this journey is discovered on the alternate version of area 2, Hollow Hives. If you have no clue how to get to Hollow Hives, then just look for beehives.
Three beehives are scattered around Gazing Grove, one in the secret room, one on a random floor later in the area, and one right after the boss fight. Breaking all three of these beehives allows you to progress to the Hollow Hives, but remember to find the secret room or else the key is impossible to obtain.
Once in the Hollow Hives, in one of the first three rooms you can see a crystal door in the wall like this one:

The door opens only when you are playing on shard 5 or higher, so you need to be playing on the highest shard level to get the full key.
Inside the room is a glass heart structure and a riddle tablet that displays the following:

Most of this riddle is for flavor, but the “healthy” part is important! Healthy here means you have to enter the room with 6 filled heart containers.
These heart containers may seem hard to get, but it really only takes 8 heals. There are several things that you can do to get a lot of soul, like breaking pickups if you are running short on soul. If necessary, restart the run until the Hero NPC appears, as the miniboss he spawns gives a lot of bonus soul.
Once you enter this room with your fill 6 hearts, Walk towards the crystalline heart up above and it will give you a key piece.

This is only the first part of the puzzle though, as you need another piece to make a whole key.

Now that you have successfully acquired the first key piece, you need to head over to the Calm Caldarium, which is pretty simple to get to. In Arid Athaneum, there are two different snow statues scattered throughout the area. All you need to do is give a full shield to each statue and you’ll arrive there in the next area.
Inside the Calm Caldarium, there is a similar crystal door to the one in Hollow Hives:

Same with the previous door, it will only open if you are playing on shard 5.
Inside the room is a starry, shadowed heart on the lower half of the room. Above it is a tablet that reads:

The gist of this riddle is that you need to have as little health as possible.
This means that you can have only one heart container, not even any uncompleted heart containers alongside it. This heart container cannot be filled either, it has to have 0-0.5 health. Luckily, you can have as many shields as you like with that health.
Getting this low on health is as simple as spending as much health as necessary upgrading relics at the metro right before the floor.
Once these requirements have been met, simply walk up to the void heart.

Once you get close enough, the heart will dispense another key piece.
The two key pieces that you have collected will combine and you will finally get the full key you need.

The quest is not yet over though, as you still need to use the full key for one last thing…

as the name of this section implies

Open the door that you will find on the Ticking Tower Top

you will now have access to this room aslong as you play above shard 5.
going in there, a certain relic lies on the ground. If you decide not to pick it up, you cannot advance anymore in the shard system

After picking it up, continue your run like normal.
You will find that your journey is long not over after finding this.