Jekyll's dual life was going perfectly as planned until two months prior to the murder of Sir Danvers Carew. One night, Jekyll transformed into Hyde involuntarily, while sleeping. Suddenly, Jekyll realized that he was in great danger of being trapped in the body of Hyde permanently, and that some aspect of the experiment had moved beyond his control. The more he took the potion, the more unstable his changes became. For two months entire months, Jekyll lived only as himself. However, he soon felt the need to free his evil side, and in a moment of extreme weakness, took the potion.