This morning there was yellow police tape across the entrance to the Park and a police car parked behind it. And silence, and nothing but beauty in the Park: the path around the Meer, florid; dewy swings and seesaws in the playground. I wondered what it all meant and peered pruriently over the old, low wall for signs of something strange and awful. All was utterly calm. At the corner more cop cars had gathered. A man surveyed the northeast corner of the Park through the lens of a Channel 5 news camera. Photographers wandered the sidewalk, their beige telephoto lenses bouncing on their haunches. A couple of cops were chatting with a young black man – could this be a witness, a suspect, some agent of the invisible, enfolding drama? But he said goodbye, reaching out his hand – they took it happily, eagerly, and he was on his way.

The perimeter ended. The perimeter ended with more yellow tape and more cars. More patrol cars where I turned to get on the train, Lennox. The train at Lennox Avenue.