The Mystery Cave

The Mystery Cave is a repeating event in Undersea Solitaire Tripeaks, with its own location and a unique set of levels. 

In order to participate, tap the event’s icon on the left-hand side of the main screen. The event takes place in two caverns, each containing five platforms. Beating a level moves you from one platform to the next. You receive Coins (but not Gems) for completing these special levels, and a treasure chest awaits you at the end of each cavern. 

Reaching the end of the two caverns isn't going to cost lives, but it won't be easy. If you lose a stage, it will cost you a light stick. You only have 3 light sticks when you enter the Mystery Cave, and if you run out, you'll return to the start of your current cavern.

Mystery Cave events only last 48 hours, so move quickly if you want to get those treasure chests.