"I like reading and I had a lot of ideas for stories," said Xu.

He wrote some of them up and began posting them on Baidu. After posting the first chapter of story about tomb raiders, he was surprised to find a lot of followers, with millions of hits and replies. He received calls from book editors. Four months later, his first book was out.

Xu, then 25, quickly shot to fame, selling 600,000 copies in just a month and topping best-seller lists.

He said his imagination is inspired by his grandmother, who told him a lot of stories, especially ghost stories, and his uncle's antique store, which he says was always filled with a lot of mysterious items.

But Xu says writing is not always easy for him.

"I can write between 10,000 to 20,000 words on a good day. But sometimes, on bad days, I can only write 100 to 200 words," he said.

Xu initially attempted to conclude his series in only three books, but his publisher pushed him to write more, because the first three sold well. Under contract, Xu had no choice.

"I struggled mightily to develop the fourth story," he said.

He suffered insomnia and could think of nothing but his inability to come up with a decent plot, he said.

"I was really physically and mentally exhausted. It was a nightmare," he said. "I was really depressed."

He compared writing with Zen.

"Like practicing Zen, I have to go through sadness, happiness, pride and disappointment when I write. Through the process, I garner maturity."

Xu eventually got past his writers' block and finished not only the fourth story but the three more sequels as well. He said he will conclude the series in the eighth book.

Xu has set up a writing cooperative, to help authors who are struggling alone with stories.

He said that the writing team is open to those who have either story ideas or know how to develop a story.

"Like joint ventures between playwrights and directors, the club employs new ideas and develops them into a story," said Xu.

The comic book adapted from Secrets of a Grave Robber. [Provided to China Daily]