"“If he be Mr. Hyde,” he had thought, “I shall be Mr. Seek.”..."See in text(Chapter Two)
In this internal utterance, we glimpse a rare spot of lighthearted fun and wordplay from Mr. Utterson. More importantly, this declaration sets the ensuing plot into motion. Whoever Mr. Hyde is, Mr. Utterson is committed to tracking him down and discovering his secrets.
"It is one thing to mortify curiosity..."See in text(Chapter Six)
This phrase subtly plays on multiple meanings and connotations of mortify. Directly speaking, Utterson is mortifying his curiosity—that is to say, suppressing his desire. To mortify is also to waste away and lose vitality, a process which Henry Jekyll is undergoing at this stage of the story. Mortification also refers to death itself, the phenomenon which sparked Utterson’s curiosity in the first place.