NEW YORK: Mystical ice creatures, fire-breathing dragons, and the people caught in between return to the small screen come April 6, when HBO’s “Game of Thrones” unsheathes a fourth season that could see it crowned as the cable network’s most watched series in history.

The medieval fantasy drama’s fan base has grown substantially over its first three seasons, with sizable followings among both men and women thanks to its wrenching interpersonal relationships, complex plotting, and, being HBO, plenty of violence.

The show is based on the “A Song of Ice and Fire” series of novels by George R.R. Martin, of which five of an expected seven have been published. It takes place in the fictional world of Westeros, following more than two dozen regular characters amid a war for dominion between noble houses.

In addition to the squabbling between regions and families, the characters also face external threats, including dragons and the “White Walkers,” nearly unkillable creatures from the far northern part of the world who can animate the dead.

The third season of the show climaxed with what is now known as the “Red Wedding,” where three primary characters were treacherously murdered along with scores of others at a wedding feast. For some shows, that might be difficult to top, but cast members said this year’s season will be even more dynamic, so as to not lose momentum with a growing audience.

“There just seems to be a whole new army of people watching the show for the first time. The more fans you have, the more pressure you feel to keep up the quality of the product,” actor John Bradley, said in a recent interview along with other cast members. He plays Samwell Tarly, a member of the Night’s Watch, the ancient order that protects Westeros from threats in the frozen north.

Last year, the show averaged 14.4 million viewers across all platforms, only about 50,000 viewers shy of HBO’s most-watched show ever, the sixth season of the mob family drama “The Sopranos.”

As “Game of Thrones” has grown and its reach has expanded — it airs in more than 200 countries and territories worldwide — so too has the business of the show.

The cast members see it as well, particularly on social media. Maisie Williams, 16, who plays fan favorite Arya Stark, said she picked up more than 40,000 followers on Twitter during the off-season. She has a big fan base on other social media sites like Vine and Instagram — in part due to a goofy video she posted after the Red Wedding where she joked about the death of her “family.”

“That really blew up — I went from having about 1,000 followers on Vine to having about 100,000,” she said.

The fourth season finds numerous major characters in King’s Landing, the capital city of Westeros, where they are gathering for the impending wedding of Joffrey, the cruel, young king who stands shoulder to shoulder with the more notable villains in television history.

There are new faces, too, most notably Prince Oberyn Martell, nicknamed the “Red Viper.” The prince comes to the capital to attend Joffrey’s wedding but also has ulterior motives, like so many on the show.