Read the excerpt from chapter 4 of The Strange Case of Dr. Jekyll and Mr. Hyde . At this moment, however, the rooms bore every mark of having been recently and hurriedly ransacked; clothes lay about the floor, with their pockets inside out; lock-fast drawers stood open; and on the hearth there lay a pile of grey ashes, as though many papers had been burned. From these embers the inspector disinterred the butt end of a green cheque book, which had resisted the action of the fire; the other half of the stick was found behind the door; and as this clinched his suspicions, the officer declared himself delighted. How does this excerpt develop the plot?