HOUSTON -

Thousands of screaming fans will pack NRG Park Friday night, when the London-based boy band One Direction takes the stage.

For hours, dozens of girls stood in the blazing hot sun outside of the St. Regis Hotel, waiting for their chance just to get a glimpse of the band, One Direction.

"It was crazy, we were like crying in the street, then we saw Liam's car pull in and I was crying," said one superfan.

Some traveled from San Antonio in a One Direction tricked-out van.

"We are really excited. If One Direction saw us that would be cool," said fan Brooklyn Purcell.

Others were a little more undercover.

"We have been waiting here for four days. We are from Louisiana. We drove in and we have been sleeping. We had the night here and before that we have been sleeping in the car," said fan Cassidy Hayes.

She and her friends follow them all over the country, hoping to meet the musicians. They have paid attention to detail and learned the signs, and this trip, it paid off.

"A black car came out of the back and we recognized the license plate so I followed them to a Brazillian Steak House, and when they came back out they let us meet Niall and talk to Niall and he was very nice," said Hayes.

Local 2 even hit the streets and The Galleria mall searching for the band, but the boys were nowhere to be found.

On Twitter, Niall was spotted in The Galleria taking photos with fans, visiting Johnson Space Center, and he and Liam even hit a bucket at Top Golf. Liam even took the ALS ice bucket challenge while he was here.

Millions of fans have watched their music videos on YouTube and on Friday night, thousands will be able to see them perform live at NRG Stadium.