Be careful. Especially if you're going to Halloween Horror Nights.

You never know who is going be scaring folks at the Universal Studios Hollywood horror event.

Lupita Nyong'o made a return to her horror movie "Us," visiting the maze on Saturday. Needless to say, visitors who came across her villainous doppelgänger character  received the fright of their life when they found it was the real thing.

"I got crazy," Nyong'o wrote on her Instagram account.

Sure she was scary, but the best part of the visit was that Nyong'o was definitely truly freaked out as well going through the maze.

The actress proved to be an excellent visitor to the attraction, which runs until Saturday. Walking through with her two sisters and her mother, she could be seen jumping  in fear, screaming and sprinting through some of the scarier sections. This was not acting.

And when properly motivated, the Oscar winning actress can definitely move. She made it clear she'll take more upbeat fare in the future to avoid repeating another Horror Nights visit.

"That is definitely my last horror film," she said on the video.