After the unicorn nudges you awake, you get up and decide to visit the flowers, before you take your broom and fly back to Hogwarts.

After you visit the flowers, you know it's time to go back.  You're not supposed to be out at night alone, especially in the forbidden forest.  You get your broom and walk back through the tall, shady, trees and back through the opening, out of the door, and into the Forbidden Forest.  Then you start your fly back over the forest, and you see Hogwarts looming ahead of you.

click Hogwarts to go back to Herbology class.