A Mystery

It was the mystery of the missing  NOUN. I couldn't find my  PLURAL VERB anywhere one day, which was  ADJECTIVE because I really  PAST TENSE VERB them. My sister was the  ADJECTIVE suspect. The  ADJECTIVE suspect was  PERSONS NAME . First we had to  VERB each person's alibi. That means, what were they   ING VERB when the  NOUN went missing. Suddenly all the lights went  COLOR and nobody could see. When the lights came back  ADJECTIVE ,  PERSONS NAME was lying on the floor, lifeless. I guess that  PAST TENSE VERB the mystery.