Chapter 8 -9

For some months, this behavior continues until Jekyll, "had gone to bed Henry Jekyll, [and] had awakened Edward Hyde." Jekyll was alarmed that he transformed into Edward Hyde without the assistance of the potion, and became concerned that the character of Hyde might irrevocably take over. Concerned that he had overstepped his bounds, Jekyll chose to give up the freedom of Hyde and for two months maintained the identity of Dr. Jekyll. Unfortunately, he was tortured with Hyde's longing to freely take part in evil doings, and he once again took the potion. During this transformation, Hyde brutally murdered Carew. Because of the manhunt for Hyde, Jekyll swore off ever again making the transformation and set out to try to remedy the evil inside of him.
Unfortunately, at this point Jekyll had given too much power to his evil side. Hyde was an irrevocable part of Jekyll's character, and the many transformations and evil behaviors only strengthened Hyde's power. One night, while contemplating Hyde's deeds, Jekyll spontaneously transformed into Edward Hyde. Because his dual identity was a secret to all members in his house, he realized he could not walk through his house to the laboratory to retrieve the potion's ingredients. Therefore, he sent the urgent letter to Dr. Lanyon. After successfully turning back into Dr. Jekyll, he went home once again but every time he fell asleep, he reverted to Mr. Hyde. Soon, his potions failed to work, even at double strength, and he ran out of the specific medicine needed. While living in the cabinet apartment and not allowing any of his servants to see him, Hyde launches a desperate but unsuccessful search across London for the potion ingredients. When Poole and Utterson finally break into the room, Hyde kills himself, thus finally releasing both Jekyll and Hyde.