The will which Dr Henry Jekyll gave to Mr Gabriel Utterson stated that is Jekyll was to die or go missing for 3 months, all of his possessions were to go immediately to Edwrd Hyde. Utterson, being a good friend of Jekyll, was suprised and confused, because he has never heard of this Hyde before. He thought Jekyll was being blackmailed by Hyde.
There were actually two wills in Dr. Jekyll and Mr. Hyde. The first, as was already mentioned, names Hyde as the sole beneficiary of Jekyll's rather large estate if Dr. Jekyll died or disappeared. Mr. Utterson guessed that Hyde had blackmailed Dr. Jekyll in order to get his money, but in truth Dr. Jekyll named Mr. Hyde as his heir so that if he were to fully succumb to that evil self he would not be without all the resources he had as Dr. Jekyll. Later, Mr. Utterson finds a revised will, where all the terms are the same, but Jekyll has changed the beneficiary from Mr. Hyde to Mr. Utterson.