♠️ Additional Heap — this is a secret card on the field located to the right of the main deck. The card is hidden in a safe with a counter.

♠️ To unlock the secret card, play solitaire and collect any cards — each one will reduce the number on the counter.

♠️ When you collect the required number of cards, the door will open, revealing the secret card that can help you complete the level faster.

♠️ Once the extra card is unlocked, you can collect cards using it.