Lanyon helps Utterson solve the case when he describes the letter given to him by Jekyll and his thoughts and reactions to the transformation. After he witnesses the transformation process (and subsequently hears Jekyll's private confession, made to him alone), Lanyon becomes shocked into critical illness and, later, death. Poole is Jekyll's butler who has been employed by him for many years. Poole serves Jekyll faithfully and attempts to be loyal to his master, but the growing reclusiveness of and changes in his master cause him growing concern. Finally fearing that his master has been murdered and that his murderer, Mr Hyde, is residing in Jekyll's chambers, Poole is driven into going to Utterson and joining forces with him to uncover the truth. Utterson joins this Scotland Yard inspector after the murder of Sir Danvers Carew. They explore Hyde's loft in Soho and discover evidence of his depraved life. A kind, 70-year-old Member of Parliament. The maid claims that Hyde, in a murderous rage, killed Carew in the streets of London on the night of 18 October. At the time of his death, Carew is carrying on his person a letter addressed to Utterson, and the broken half of one of Jekyll's walking sticks is found on his body. A maid, whose employer - presumably Jekyll- Hyde had once visited, is the only person who has witnessed the murder of Sir Danvers Carew. She saw Hyde murder Carew with Jekyll's cane and his feet. Having fainted after seeing what happened, she then wakes up and rushes to the police, thus initiating the murder case of Sir Danvers Carew. Literary genres that critics have applied as a framework for interpreting the novel include religious allegory, fable, detective story, sensation fiction, Doppelgänger literature, Scottish devil tales, and gothic novel. The novella is frequently interpreted as an examination of the duality of human nature, usually expressed as an inner struggle between good and evil, with variations such as human versus animal, civilization versus barbarism sometimes substituted, the main thrust being that of an essential inner struggle between the one and other, and that the failure to accept this tension results in evil, or barbarity, or animal violence, being projected onto others. In Freudian theory, the thoughts and desires banished to the unconscious mind motivate the behaviour of the conscious mind. Banishing evil to the unconscious mind in an attempt to achieve perfect goodness can result in the development of a Mr Hyde-type aspect to one's character.