The trap is set

He could relax now, he thought, as he looked at the computer screen. In a little while all the pain and humiliation would be over. His tormentor would be dead. For so long he had  fretted over the details of the death he planned for him. He wanted to make sure they knew it was him. He wanted them to know why he had done it. What he did not want was for it to be an easy death. A quick end would be no revenge on that scribbling fiend. Hence the obsession. It was the obsession that had almost undone him.   

At first they had thought that he was just having a laugh. They had joined in the joke at first, imagining all sorts of gruesome ends for his enemy. All of them, they thought "hilarious". Then they had begun urging  him to relax, to take it easy, to forget it.  After a while, she had begun to eye him curiously. It was then, just in time, he realised the danger. He had better  pretend to have have got over it. He would keep quiet. He would plan the details secretly. And indeed he had kept the secret well. She did not look anxiously at him now. She would if she knew.

Now everything was in place. He lay back in his seat smiling. It was the first time he had smiled in many months, though he had often grinned as some of the details of his scheme had fallen into place. He was imagining what would happen in a very, very little while.  In his mind he could hear the police sirens. They were on a fool's errand.  The wailing of the ambulances would be gruesomely appropriate, for they would be too late. He pictured the panic and confusion in the house. It would be of no help. Of course, it would be the strange smell they notice at first, uneasily wondering what it could be. He hoped it was she who had dared opened the door first. She who had claimed to be a friend! Well, she was the wretch's wife, so  it would be her the hellish stink would hit first. She would be thrown into uncontrollable retching. There would be some satisfaction too in her painful, endless heaving.

She was not the real target, though. It was her vile husband. Her jabbing spasms would end. But they were just the beginning of the horror. He tried to remain calm as he thought of it. But his breathing quickened as he thought of her finally venturing, trembling, into the room. She would anxiously call the blackguard's name. It would take time for the creeping, green mist to clear enough to make anything out. Slowly she would be peering with mounting terror at a contorted figure thrown back from his desk - its desk. Could that be him? She would want to retch again as the sickening sight revealed itself with disgusting clarity. But only a single, piercing, horrified cry would force itself up from her stomach. With trembling hands she would try to stifle the scream in her mouth In vain!. It would tear itself out, reverberating throughout the whole house. What could the disgusting creature b be? Her husband? The black, oily skin had not provoked  the horror. Nor had the grotesquely twisted limbs, revolting though they were.  It was that face! That reptilian skin, those staring, fear-filled eyes, that gaping mouth, that  lolling tongue. These told of an unendurable, unending  agony. It was a fitting end to a loathsome creature, he thought as he glanced at the ticking clock.

"Some odd word choices," his adversary had said. That had merely bemused him. It was the suggestion that he needed to check some grammar that had flung the switch in his head. Now the trap was set. His enemy would soon be logging on to Writing.com to dish out some more some "helpful criticism". This time the monster would be repaid in full for his humiliating barbs. The moment he presses "Enter" the hellish gas will be released. Then the oft-imagined scenario would play out in slow, agonising, horrifying detail. Exactly as planned.