A favorite location of all three cats is the dirty laundry hamper. They let themselves into the closet and find the most comfortable place to hang out, and evidently that is the basket of laundry. Pierre obviously did not like being interrupted during his post-mid afternoon pre-dinner nap.
What happens after Pierre hides behind the curtain? He usually pounces on Newton and they fight each other for a while (all in good fun) then chase each other around the house.
Pierre started this when Newton was a cute little 2 pound kitten and felt very superior, never expecting him to grow up to be bigger than Pierre. They are good buddies and seem to enjoy each other during play time.