They came to mix potions. They came to decorate magic wands and black, pointed hats. They came to guess the number of jelly beans in a jar. They came to participate in a costume contest. At least one young girl’s birthday gift was to get to come to the event with her big sister.

And some of them were there to buy a book.

A crowd estimated at between 300 and 400 people crowded the Brownwood Hastings story Friday night in advance of the 12:01 a.m. Saturday sales kickoff for “Harry Potter and the Deathly Hallows.” It is the seventh and final volume in the series that has touched off marketing bonanzas throughout the world.

“It was pretty packed,” Hastings manager Ray Boslee said. “It was as many or more as we had the last time a Harry Potter book came out.”

The party officially started at 10 p.m., and people of all ages jammed the store throughout the evening.

“What’s amazing is how many adults read those books,” Boslee said. “It’s basically a kids’ book, and children’s and young person’s book. A lot of parents read ‘Harry Potter’ to their children or grandchildren, and they enjoy it as such as the kids.”

The store has been accepting reservations for the book, and did so as well Friday night prior to the moment when sales were allowed to begin. Advance sales were so brisk, the store received an additional allotment, Boslee said. Many who had reservations decided to avoid the crowds and pick up their copies later in the weekend.

Boslee had no immediate sales figures Saturday, but he said the store still had copies to sell.

Boslee was impressed with the overall knowledge the Friday night crowd had about the Harry Potter series.

“While they were in line waiting to buy their copies, we had a trivia contest about Harry Potter,” Boslee said. “They were able to answer every question, except for one.”

Boslee said the Harry Potter series has proven that young people can be inspired to read, and that teachers — including his wife — have told him that it’s a positive thing for literature as it involves the future generation.

“At least they’re reading something,” he said.