In the final chapter of The Strange Case of Dr. Jekyll and Mr. Hyde, what does Jekyll/Hyde do at last?
Lanyon is summoned by a strange letter to come to Jekyll's laboratory, where he witnesses one of the Jekyll-Hyde transformations taking place. Jekyll confesses to his crimes commited while taking on the identity of Hyde and describes the impish delight he took in committing them. The end of the story implies that he kills himself by taking a fatal poison (incidentally concocted from chemicals Lanyon had brought upon Jekyll's request), since the only thing left in store for him - as Jekyll or Hyde - are the gallows. So the tale ends by the doctor's self-destruction.