Mr. Enfield is a curious cat that tries to sneak around Mr. Hyde. The fact that Mr. Hyde's actions and features is intreaging and creates suspiction. So Mr. Enfield finally spots Mr. Hyde and doesn't find anything to be worried about, yet is still ponderous. So he also tryes to find information from Dr. Jekyll, but he wasn't home. Yet, the trip wasn't for nothing, the maiden reveals facts about Mr. Hyde's and Dr. Jekll's relationship. So in conclusion, I think that the two are the same person in disguise.