When it seems that the abominable Mr. Hyde has disappeared, Dr. Jekyll feels able to venture into society once more. No longer shut away in his laboratory, he can visit the many friends and acquaintances he's kept at arm's length for so long. Perhaps partly out of a sense of guilt Dr. Jekyll throws himself back into the extensive charity work for which this generous man has gained such renown. He also starts attending dinner parties, picking up from where he'd left off before he started turning into Mr. Hyde. Before long, Dr. Jekyll is back to his old self; it's just like the good old days. It seems that his brief dalliance with the dark side of human nature is over and that the good doctor can kick back and relax.

But suddenly it seems that Dr. Jekyll has reverted to his secretive, anti-social behavior. Utterson calls on him three times only to be denied entry on each occasion; the doctor has locked himself away in his room and does not wish to see anyone. Determined to get to the bottom of things, he visits Dr. Lanyon to see if he can shed any light on what's up with Jekyll. When he gets there, he's shocked at Lanyon's terrified, haunted demeanor. Lanyon claims to have had quite a shock himself and tells Utterson that he—Lanyon—will be dead within a matter of weeks. Lanyon won't reveal what brought any of this on, but it's clear that he's had a truly terrifying experience.