EXCLUSIVE

A star from "Firefly" claims an obsessed fan has been at her doorstep, demanding a million bucks and burning incense around the perimeter of her property ... so she ran to court for protection.

Summer Glau -- who's also been featured in "Arrow" and "Sequestered" -- claims Gary Gin came to her house in February and said he wrote the sequel to "Serenity" and demanded $1 million for his work. Summer -- who is 6 months pregnant -- says in legal docs her fiance confronted the guy.

But Gin didn't leave. Instead, the 33-year-old actress claims he burned incense around her house to make a statement. But that wasn't all. She claims 3 weeks later she got a package and when she opened it it looked like a bomb ... filled with bird feathers, tree branches, wires and bones.

She included a 4-page letter she received from him, in which he says, "Relying on telepathy to communicate with you has been problematic for me." He wanted an in-person chit chat.

The judge saw it Summer's way, and granted a restraining order.