Stephen Cannell says Act Two belongs to the Villain.
The Villain can help define the Hero. Ideally, the Hero expands in terms of stature and quality as the Villain evolves from prospective opponent to actual opponent.
Your Adversaries must be in motion. Adversaries should not be standing around, waiting to be caught.
At the end of Act Two is the second act curtain. This is the destruction of the Hero’s plan. At the end of Act Two the Protagonist should be almost destroyed, and at the lowest point in the drama, either physically and/or emotionally.
He (or she) is flat on his back and it looks like there is no way in hell he can succeed.