A Midsummer Night's Dream 3.2 Performance: Puck Lines 379-388

The transcript describes a scene where knights and dragons swiftly cut through clouds, followed by the arrival of Aurora's harbinger, prompting ghosts to retreat to their resting places. These spirits, fearing exposure, exile themselves from the light and consort with the night.

What is implied about the spirits that have already been buried?

What does the speaker mean by 'consort with black browed night'?