Answer:
The discovery of the other half of the stick.
Step-by-step explanation:
The discovery of the other half of the stick is the event that is most likely to increase suspense about the nature of Dr. Jekyll and Mr. Hyde's relationship. The stick is believed to be the same one that was used to kill the member of Parliament in the street. The murder was witnessed by a maid, and the fact that this piece of evidence is found shows how evil Mr. Hyde can be.