Is a plot an adjective?
No, a plot is a noun. To plot is a verb.
Yes, the word 'fascinating' functions as an adjective, a word used to describe a noun. The word 'fascinating' is the past participle, past tense of the verb to fascinate. The past participle of the verb also functions as an adjective and a gerund (verbal noun). Examples: The way he tells the story is fascinating the children. (verb) She has a fascinating idea for a movie plot. (adjective) I would describe it as fascinating. (noun)