Dr. Hastie Lanyon Timeline and Summary

Mr. Utterson visits Dr. Lanyon to ask about Dr. Jekyll and Mr. Hyde.
Dr. Lanyon admits that his relationship with Dr. Jekyll is no longer a close one.
Dr. Lanyon has never heard of Mr. Hyde.
After the death of Sir Danvers, Mr. Utterson and Dr. Lanyon dine at Dr. Jekyll’s house, and all seems well.
Several days later, Dr. Lanyon is near death. He looks much older and paler and seems terrified.
Two weeks later, he dies and leaves a narrative with Mr. Utterson.
The narrative details his witnessing the transformation from Mr. Hyde to Dr. Jekyll.
Most likely, the disturbing scene of watching Jekyll become Hyde was too much to bear, causing the death of poor Mr. Lanyon.