Perhaps add a means for the narrator to lock out cards from play.

For example, in my current game one of the Obstacle cards is an escape the current environment card. However, the players pursued another Obstacle card, that caused them to pause. I'd like the ability to say. 'Your progress toward escape was halted, and until the current card is completed, you can't play any more on the Escape card.' basically lock players from playing cards to resolve this card.