The death of Ricardo part 3

As Kelly lay in the store room the others lay in different rooms experiencing the same intense paranoia. All except David Addison and M who sat in the sitting room. M lay on the couch eyes closed as David Addison paced in front of him.
"Well now M you appear to be more resistant to the drug than the rest of them. You see I had spiked all of Ricardo's alcohol, which is why I brought my own bottle of Merlot. I guess while I wait for you to succumb to the effects of the drug a bit of Monologing should pass the time. You see Ricardo and I were business acquaintances, we exported high quality extremely rare chemicals for personal use. I created them and Ricardo distributed them. We had it sweet the Spanish authorities had no idea who we were or even that we were creating the drugs in there country. However after I created my latest drug I needed someone to test it out on as Ricardo was away I felt it would be best to try its effects out on his lovely wife and children. I never liked them you know and they were always scheming to get rid of me. HA.HA” he laughed “that is to say I always dreamed of getting rid of them. Do you know his wife actually wanted an equal share in the profits?” he turned and looked at M, “Well of course you wouldn’t. Well after they died, painfully I might add Ricardo became shall we say a little upset and threatened to go to the cops. However firstly he decided to flee the country and ended up here. By a stroke of luck I stumbled across Roberts blog site which mentioned a man called Ricardo who had moved here from Spain under suspicious circumstances. Now all you people have to do is die and I can return to Spain and enjoy my new life.”
“I’m afraid that you won’t be enjoying your new life or for that matter any life at all” said a voice which sounded like M’s but infinitely more chilling.
“What….How…….Who” David Addison stuttered.
The man who had once been M laughed, “What am I doing? Well I’m going to kill you. How am I able to walk after your little drug! I have been filled full of drugs for my whole life as the idiot doctors tried to cure what they did not understand. Who am I. I’m X, take a good look as I will be the last thing you ever see.”
The next day the cops went back to investigate Ricardo’s murder scene and found every room in the house covered top to bottom in human blood. No bodies were ever found and no one was ever arrested.