Use examples from the book, describe the dark shadow which appears at the end of chapter 4

Though Meg can’t adequately explain it, it is “dark and dreadful” and it covers the light of the stars. Calvin wants it to go away because he feels it is evil, and soon they can no longer stare at this darkness. Mrs. Whatsit descends back into the valley and Meg asks whether the dark thing they saw was what her father is fighting.

I would describe it as well like Meg "dark and dreadful. i also fell it is evil like Calvin. Everyone says evilis like a dark shadow but that is what it is.