Shashi Tharoor has an exceptionally full and busy life in New York City.

This week, for instance, his evenings are tied up with three official dinner engagements, a television interview and a speech at the opening of an exhibition.

He also has a new job at the United Nations -- although a temporary assignment -- as the interim head of the international body's Department of Public Information. And to top it all, he has just finished writing his third novel (and sixth book) -- an examination of a communal riot in India, aptly titled Riot.

"I think many of us inhabit several worlds at the same time," he says from his new corner office on the 10th floor of the UN building, which has a panoramic view of the East River.

Dressed in a suit during the day, the 45-year-old Tharoor is a civil servant at the United Nations with 18 years of experience behind him.

On evenings and weekends, often dressed in a kurta, he is an Indian living in New York, interacting with the expatriate community from India, at a Holi do or an Onam function.

And finally, he is a writer from India whose audience is first and foremost Indians and to a lesser degree others, who may have some interest in his home country.

His three worlds and identities co-exist in a balance. He sees no contradictions between them. He inhabits all of them.

Riot is set in 1989 in Uttar Pradesh. It will be published in August in India, and the following month in the US. The book is a departure from his previous works -- less satirical, and more of an exploration of religion, cultural differences and human relationships.

Another departure... for the first time he introduces an American character in his book, a woman who gets killed at the beginning of the book. That's not giving away the ending of the book, he explains with a smile.

Recently, when asked to describe the book in one sentence, he said: "It's about love, hate, cultural coalition, the ownership of history and the impossibility of knowing the truth."

To learn about the mechanics of a communal flare up, Tharoor accessed a report written by a college friend, who was the top IAS officer during a similar riot in Madhya Pradesh.

But Tharoor sees no inconsistency in creating a fictitious world, set in Uttar Pradesh, from his apartment in Manhattan's Upper East Side. He may have lived away from India for substantial lengths of time, but his memories are clear and fresh. What is key here, he says, is a writer's ability to empathize with and recollect the experiences that are being brought up in the book.

"Let's not forget that novels and books are often written in various kinds of circumstances," he says. "There are great novels about the West that were written by writers holed up in a garret somewhere or on a beach in Spain. Jawaharlal Nehru wrote the Discovery of India in a jail where he wasn't hearing views of learned historians."

Tharoor says he writes when he can, but usually sets aside weekends, with hardly any breaks, other than for a meal or to drink tea. He never carries his laptop with him on missions abroad and therefore does no writing while traveling.

"One needs time and space inside one's head to write," he says. "One of the frustrations for me, and why it has taken me so long to produce so few novels, is that to create the alternative universe that you write about, you need a little more coherent collective space than I have in my life."

His first work of fiction, The Great Indian Novel , written in 1989, was produced while he was posted in Geneva and his twin sons were small (they are now 16).

"When children are that small, wheeling them in a pram for a weekend walk and occasionally changing their diapers fulfilled my obligation, and I could write on weekends as well," he says.

Most of his second novel, Show Business, was written in New York in 1992, when he was between postings. His family was away on home leave and he had every evening and weekend to himself.

Writing the next two books, a collection of essays -- India: From Midnight to the Millennium in 1997, and now Riot have been much more difficult.

Tharoor started to write at a very young age -- his first published work dates back to 1966, when he was 10 -- and writing comes very naturally to him, he says. But the reality of life and his belief in the ability of the United Nations to make a difference in people's lives has compelled him to maintain two parallel careers.

"I have published five books and I seem to specialize in getting wonderful reviews and very modest sales!" he says. "So the option of writing full time was simply never on, when I had a family and children to educate."

But, beyond that, the work he does at the UN is important to him. He holds a Ph D from the Fletcher School of Law and Diplomacy at Tufts University and did not join the UN just "to get a paycheck to pay the rent" and to support his writing career.

At the DPI, he brings to the table his journalism background, as well as his strong knowledge of the UN's operations. He holds a passionate conviction that information is key to success of the UN.

"I tell people you are not coming to work in the morning to write a press release or produce a poster," he says. "You are coming to work because peacekeeping will not succeed if the world does not know what the peacekeepers are doing. The battle against AIDS will not be won if we cannot raise the conscience of the world through our information activities."

He started his UN career in 1978 as the head of the high commission for refugees operations in Singapore, where his group was involved in rescuing the Vietnamese boat people from the high seas and to eventually resettle them in other western countries.

"I knew that I could put my head to pillow, each day, at night knowing the things I had done during the day, had made a difference to real human beings' lives," he says. "And to see the results of your efforts in the eyes of the real human beings is an invaluable experience and richly satisfying."

Later, Tharoor was a part of the UN's peacekeeping efforts in the former Yugoslavia. Although another high profile job -- he was the secretary general's special aide in the peacekeeping department -- the results in this case were not so apparent.

But through the long negotiations, while ethnic violence tore Yugoslavia apart, he was fully aware that he could put his own "smudgy thumbprints on the pages of history in one of the great human events of our time."

And at his last position -- as the secretary general's director of communications and special projects, he has seen the inner workings of the UN during the post Cold War era.

Tharoor's stature, as a writer based in New York and as a UN diplomat, often brings him invitations for speaking engagements from college campuses and other Indian community groups. He says he understands the minds of the NRIs in the US to some extent, although he does not face the same struggles as they do -- trying to be accepted as Americans. He maintains his Indian passport and his identity.

"I am not seeking to be accepted as an American," he says. "I am a foreigner and I admit as such. I don't face some of the issues of engagement with American politics and American public life which Indians are grappling with now. From the outside I support them and I admire them."

The parallel lives of Shashi Tharoor move in remarkable harmony. There are three or four other ideas for books that he has not found time to execute. He may or may not ever get to those projects. But he intends to continue, both, his professional life, as well as his writing.

"So far, anyway, no one has suggested that one has affected the quality of the other. When that day comes I will have to decide and I will have to make choices."