What does the chorus tell you will happen in play Romeo and Juliet?

In the prologue of "Romeo and Juliet," the chorus predicts that the play will unfold as a tragedy. It foreshadows the ill-fated love affair between Romeo and Juliet and the tragic consequences it will bring upon both their families and the city of Verona. The chorus proclaims:

"Two households, both alike in dignity,

In fair Verona, where we lay our scene,

From ancient grudge break to new mutiny,

Where civil blood makes civil hands unclean.

From forth the fatal loins of these two foes

A pair of star-cross'd lovers take their life;

Whose misadventures, piteous overthrows,

And their deaths' passage, scourging of this sight

Lie all within the verge of this confine.

Is now the two hours' traffic of our stage;

The which, if you with patient ears attend,

What here shall miss, our toil shall strive to mend."

The chorus sets the tone of the entire play, hinting at the impending doom that awaits the main characters due to their families' feud and the star-crossed nature of their love.