Player A plays an Attack card.
The Attack cards takes effect (ending their turn, meaning they don’t have to draw card from pile, and giving Player B two turns).
Player B plays an Attack card, as the first of their two turns, ending that turn without having to draw a card. Their remaining turns, which would be one, plus two turns, pass to Player C. Player C now has to take 3 turns.
Player C plays an Attack card, as the first of their 3 turns, which immediately ends that turn, meaning they don’t draw a card, and passes their remaining 2 turns, plus two new turns, to Player D.
Player D plays a Nope card.
The Nope card takes effect (canceling the Attack card which Player C played for the first of their 3 turns. Player C now has to play 2 more turns.