Read the excerpt from The Strange Case of Dr. Jekyll and Mr. Hyde. Mr. Utterson had been some minutes at his post, when he was aware of an odd light footstep drawing near. In the course of his nightly patrols, he had long grown accustomed to the quaint effect with which the footfalls of a single person, while he is still a great way off, suddenly spring out distinct from the vast hum and clatter of the city. Yet his attention had never before been so sharply and decisively arrested; and it was with a strong, superstitious prevision of success that he withdrew into the entry of the court.

What is the mood of the excerpt?

sentimental
regretful
lighthearted
suspenseful