Hi Same, if you are in the opium den, there was one fella that I couldn't kill without taking a lot of damage. This might be the one, not sure. I also stayed Dr. Jekyll until I was ready to move to the next area. If you have everything that you need and enough health, I would just try to continue on to the next level. I'm pretty sure that you get full health once you move into the next area. Sorry that I couldn't be of more help. Good luck