"The Lottery" is available to read for free on the website linked below. Here is a brief summary.

The people of a small town gather for a yearly ritual. As they gather, some of the history of the ritual is explained, although not the purpose or all the details. Throughout the ritual, the townsfolk comment on how the ritual has changed. When everyone is gathered, each head of a household selects a piece of paper from a box. When the papers are opened, Bill Hutchinson is singled out. Each person in his family then takes a paper from the box, and Tessie Hutchinson, his wife, gets the piece of paper with a black spot on it. She is selected by the ritual, and the other townsfolk stone her to death to bring the town good luck and a good harvest.

"The Lottery" begins on a beautiful summer day.  We know the date (June 27th) but aside from that our narrator avoids any specific details surrounding the town's location.  This gives the reader a sense that the events that will be described can happen at anytime and in any city.

The people of the village began to gather in the square, between the post office and the bank, around ten o'clock; in some towns there were so many people that the lottery took two days and had to be started on June 2th. but in this village, where there were only about three hundred people, the whole lottery took less than two hours, so it could begin at ten o'clock in the morning and still be through in time to allow the villagers to get home for noon dinner.

The reader knows that the town is gathered for a lottery if some sort, but there is no explanation to the reason behind the lottery or even what the prize will be.  The detached third person narrator instead describes the event in a matter of fact tone.

Mr. Summers comes with the town's black box (of which the narrator points out is not the original box) filled with papers for the townspeople to draw from.  He then takes the time to ensure that everyone remembers the rules of the lottery (though since it's been done for so many years, no one really listens "The people had done it so many times that they only half listened to the directions.") After they make sure everyone agrees on the rules, the had of each household draws from the lottery.  Despite Mrs. Hutchinson's protests, it is determined that Mr. Hutchinson "has it."

Then the voices began to say, "It's Hutchinson. It's Bill," "Bill Hutchinson's got it."

Now each member of the Hutchinson family draws from the box including 12 year old Nancy and their youngest son, little Dave.  A black spot on her paper reveals that Mrs. Hutchinson (Tessie) has "won" the lottery.

To the surprise of the reader, the town members begin picking up stones.  Piled around the crowd, waiting for this moment were piles of stones.

Although the villagers had forgotten the ritual and lost the original black box, they still remembered to use stones. The pile of stones the boys had made earlier was ready; there were stones on the ground with the blowing scraps of paper that had come out of the box Delacroix selected a stone so large she had to pick it up with both hands and turned to Mrs. Dunbar.

In a hurry to be done with the who ordeal, the town (and even little Dave) begin throwing stones, rocks, and pebbles at their friend, neighbor, and mother- Mrs. Hutchinson.