In a future, we are going to need get event fragments, pay 100 diamonds to get 1 fragment. After 1000 fragments, you can create 1 event ticket. Use the ticket to participate in an event. After use the ticket, you will receive the first event mission, but because you were able to finally get the pass the last day of the event, you only have 1 day to complete it.
You need another 1000 fragments to particpate in the next event.
When you use the ticket, you receive your first mission, after complete it, you must pay 10 diamonds to get 1 fragment to unlock the next mission, after 100 fragments, you unlock the 2nd mission.
In order to receive one of the rewards for complete X amount of missions, you must pay 50 diamonds to get a fragment to receive 1 of those rewards, you need 10 fragments of that.
Also, if you can finally complete the event building, you must pay 25 diamonts per fragment up to a total of 25 to receive the daily production of that new building, in a form of a locked box which can be opened with a key, you need pay 5 diamonds per key fragment up to 50 to unlock the key.
After open the box, you receive fragments of that production, open 100 boxes to have enough fragments to finally have the whole production.
Wellcome to: Fragments of Fragments, or FoF.