The Secret Slot is a feature that lets you get another gem after the ritual.
In order to start the Secret Ritual, you need to fulfill the following conditions

1. Have Suns / Super Suns;
2. Be in a dungeon where the ritual lasts 12 hours.
How exactly it works:
1. Start a regular ritual. "!" sign appears next to the Secret slot icon. This means that now you can activate a secret ritual.
2. Go to the Secret Slot. It is not activated. To activate it, you need to pay 1 Supersun or several ordinary Suns.
The number of Suns can vary depending on the ritual. The more valuable gems you use in the ritual, the more expensive the secret ritual will be.
3. Activate the secret ritual. Once activated, a number will appear at the top of the secret slot. This is the rating of the guaranteed gem that you will receive if you no longer spend currency to increase the rating of the gem from the Secret Slot.
4. If the currency button has disappeared from the totem and only the orbs button remains, this means that you've activated the gem with the maximum rating. You can use the orbs to speed up the ritual
 and receive the gem from the Secret slot.
5. If you are attacked during the ritual and your gem is stolen, both the regular ritual and the secret ritual will stop. When the ritual is restarted, the rating of the gem in the Secret Slot will not change in any case. You don't need to spend any additional resources to resume the Secret Ritual.
6. The secret ritual will end at exactly the same time as the regular ritual. After that, the secret gem will be added to inventory.