AFTER DARK ON OCTOBER 15, 2011, as the worldwide "United For Global Change" march drew to a close in Spain, a group of demonstrators held an assembly in Madrid's famous Puerta del Sol plaza. The day had been a tremendous success: marchers had turned out in more than sixty Spanish cities and reports were coming in that people had demonstrated in over eighty countries. A picture was emerging of the unified global response to the economic crisis many had been dreaming of. At that very moment across el charco — the puddle, the colloquial Spanish way of referring to the Atlantic Ocean — protesters in New York City were flooding into Times Square. "It's decided that the thing can't just end like this," Alfonso F., an activist present, told me in April, recalling the assembly. Some robust gesture was called for, an act of punctuation to end the day and at the same time extend it. Not a block away, on Calle Carretas, one of the streets leading into Sol, an abandoned hotel stood — the Hotel Madrid, as the wanly dulled brass letters above the entrance read, the i missing. After much debate the assembly resolved to occupy it.

After jimmying the doors open a group of people headed into the hotel while a crowd of at least a hundred remained in the street, spilling out around the entrance. It was past two in the morning. In a YouTube video the scene has the heady feeling of a block party infused with a sudden collective purpose. People chant and take pictures as activists gather above in the windows of the hotel. A police van approaches, blue lights flashing. It pauses — the orange sign of the Bershka clothing store across the street reflected in its black mirrored windows — then continues on, provoking cheers and applause.

As this wee-hours fanfare tapered off a core group of forty or fifty hunkered down and installed itself in the hotel, some bringing prior experience with squats, others not. In the morning a species of press release appeared at 7:56 a.m. "sleepless" the message noted at the end; on madrid.tomalaplaza.net, an online meet-up point for activists in Madrid.

"We are a group of people who have found ourselves in an open and abandoned space in very good condition," the communiqué read.

On the night of the fifteenth of October we decided to take it over in order to put it to a social use. The building has five floors, a basement, and two terraces. It includes multipurpose halls, fully equipped rooms, storage areas, kitchens, a cafeteria, electricity, and a large quantity of materials...We invite you to participate and contribute ideas to bring to life this building we consider more than ready for a popular, open, and participatory use. Today Sunday the sixteenth we would like you to attend a series of activities during the day on Calle Carretas, such as a social forum, a picnic, debates, and whatever else occurs to us. Your support is crucial during the coming hours....