The three playing card names below have something in common. What is it, and what is the fourth card that can join this exclusive group? Hint: The "of" is important.

1. Eight of clubs

2. Ten of clubs

3. King of clubs 

4. ?????????????

Hint:

Look carefully at the letters.

Answers:

 

The 4th card is the King of hearts.

 

Explanation:

 

All four card names have no repeated letters