Chapter ten- Henry Jekyll's full statement of the case Jekyll tells his own story in his statement, sharing with Utterson how he had always felt as if there were two sides to him. His scientific studies led him to devise a potion which could turn him into the ‘bad’ part of himself; this potion caused him to change appearance so that he became Mr Hyde. As Mr Hyde, Jekyll explored his darker side and became increasingly violent until he ended up murdering the elderly man, Sir Danvers Carew. After this murder, Jekyll stopped taking the potion but found himself changing into Mr Hyde anyway. Jekyll ran out of the potion that he needed to transform back and so wrote his statement for Utterson, explaining what had happened,. Then he prepared to die, fatally weakened by the effects of the potion.