The modern-day "Sherlock" series will pay tribute to its Victorian roots in the special episode, "Sherlock: The Abominable Bride," set to air on New Year's Day.

PBS announced on Saturday that the 90-minute special would air on Saturday, Jan. 1, 2016 and stream online at PBS.com with an encore presentation on Sunday. Unlike the past three seasons where "Sherlock" first had to air on BBC in the U.K. per agreement, the special will air on the same date on both sides of the pond.

Benedict Cumberbatch and Martin Freeman will return to their roles as Sherlock Holmes and Dr. John Watson for the first time since 2014 when the third season aired. But this time, they will channel Sir Arthur Conan Doyle's original stories set in the Victorian era.

Here's the full description for the special from PBS:

"Benedict Cumberbatch ('The Imitation Game') and Martin Freeman ('The Hobbit') return as Sherlock Holmes and Dr. Watson in the acclaimed modern retelling of Arthur Conan Doyle's classic stories. But now our heroes find themselves in 1890s London. Beloved characters Mary Morstan (played by Amanda Abbington), Inspector Lestrade (Rupert Graves) and Mrs. Hudson (Una Stubbs) also turn up at 221b Baker Street."

The busy schedules of its stars Cumberbatch and Freedman have delayed a fourth season of "Sherlock," but production is set to begin in Spring 2016. PBS has not announced an airdate.

"Sherlock: The Abominable Bride" will air on Jan. 1, 2016 at 9 p.m. on PBS.

Watch the new trailer below: