AFTER WORK, I followed kathy to the park again. Sure enough, her lover was waiting at the same spot they met at last time. They kissed and groped each other like teenagers.

Kathy glanced in my direction, and for a second I thought she saw me, but no. She only had eyes for him. I tried to get a better look at him this time. But I still didn’t see his face properly, though something about his build was familiar. I had the feeling I’d seen him before somewhere.

They walked toward Camden and disappeared into a pub, the Rose and Crown, a seedy-looking place. I waited in the café opposite. About an hour later, they came out. Kathy was all over him, kissing him. They kissed for a while by the road. I watched, feeling sick to my stomach, burning with hate. She eventually said goodbye to him, and they left each other. She started walking away. The man turned and walked in the opposite direction. I

didn’t follow Kathy. I followed him.

He waited at a bus stop. I stood behind him. I looked at his back, his shoulders; I imagined lunging at him—shoving him under the oncoming bus. But I didn’t push him. He got on the bus. So did I.

I assumed he would go directly home, but he didn’t. He changed buses a couple of times. I followed him from a distance. He went to the East End, where he disappeared into a warehouse for half an hour. Then another journey, on another bus. He made a couple of phone calls, speaking in a low voice and chuckling frequently. I wondered if he was talking to Kathy. I was feeling increasingly frustrated and disheartened. But I was also stubborn and refused to give up.

Eventually he made his way home—getting off the bus and turning onto a quiet tree-lined street. He was still talking on his phone. I followed him, keeping my distance. The street was deserted. If had turned around, he would have seen me. But he didn’t.

I passed a house with a rock garden and succulent plants. I acted without thinking—my body seemed to move on its own. My arm reached over the low wall into the garden and picked up a rock. I could feel its weight in my hands. My hands knew what to do: they had decided to kill him, crack open the worthless scumbag’s skull. I went along with this, in a mindless trance, creeping after him, silently gaining ground, getting nearer. Soon I was close enough. I raised the rock, preparing to smash it down on him with all my strength. I’d knock him to the ground and bash his brains out. I was so close; if he weren’t still talking on his phone, he’d have heard me.

Now: I raised the rock, and—

Right behind me, on my left, a front door opened. A sudden buzz of conversation, loud Thank yous and Goodbyes as people left the house. I froze. Right in front of me, Kathy’s lover stopped and looked in the direction of the noise, at the house. I stepped aside and hid behind a tree. He didn’t see me.

He started walking again, but I didn’t follow. The interruption had startled me out of my reverie. The rock fell from my hand and it thudded to the ground. I watched him from behind the tree. He strolled up to the front door of a house, unlocked it, and let himself inside.

A few seconds later, a light went on in the kitchen. He was standing in profile, a little way from the window. Only half of the room was visible from the street. He was talking to someone I couldn’t see. While they talked, he opened a bottle of wine. They sat down and ate a meal together. Then I caught a glimpse of his companion. It was a woman. Was it his wife? I couldn’t see her clearly. He put his arm around her and kissed her.

So I wasn’t the only one being betrayed. He had returned home, after kissing my wife, and ate the meal this woman had prepared for him, as if nothing had happened. I knew I couldn’t leave it here—I had to do

something. But what? Despite my best homicidal fantasies, I wasn’t a murderer. I couldn’t kill him.

I’d have to think of something cleverer than that.