Guess who's coming back for 'Sherlock' season 4

The shooting for the new season of Sherlock is underway. Slowly and steadily images from the set are being posted by the cast members. 

First, it was Mark Gatiss announcing the start of the shoot and that was followed by a look at Benedict Cumberbatch's Sherlock from behind on a camera screen from the sets. Twist and diffuse is back.

Production designer Arwel Wyn Jones is fandom's most reliable tease when it comes to information about sets and props. Steady trickle from his account gives the glimpse of the modern universe of Arthur Conan Doyle's detective and his Boswell.

Goodnight from me & goodnight from him  pic.twitter.com/y03x0QqhGr

— Arwel Wyn Jones (@arwelwjones) April 15, 2016

Is there anyone home? pic.twitter.com/n62KOhcDPW

— Arwel Wyn Jones (@arwelwjones) April 15, 2016

Today's work, breakdown & budget this... #lovemywork pic.twitter.com/uZQj7b2i5w

— Arwel Wyn Jones (@arwelwjones) April 9, 2016

Happy Friday everybody  pic.twitter.com/vImv4uwrjv

— Arwel Wyn Jones (@arwelwjones) April 1, 2016

There's someone new in the chair today @rtalalay pic.twitter.com/esqknyccCq

— Arwel Wyn Jones (@arwelwjones) April 18, 2016

Little morning treat  pic.twitter.com/pYeHuLlZUx

— Arwel Wyn Jones (@arwelwjones) April 14, 2016

In the new post on the micro-blogging site, co-creator, writer Mark Gatiss tweeted a picture of himself in a nearly same fashion they did for Cumberbatch, announcing the return of Mycroft Holmes for the new season.

Back 4 (more) #Sherlock pic.twitter.com/jfTCE1e9FU

— Mark Gatiss (@Markgatiss) April 21, 2016

He did the same for Martin Freeman and Amanda Abbington who play John and Mary Watson respectively.

Back (again) pic.twitter.com/aY5P39vIqJ

— Mark Gatiss (@Markgatiss) April 20, 2016

Back 2. #Sherlock pic.twitter.com/iRAHPm5kDC

— Mark Gatiss (@Markgatiss) April 13, 2016

Talking of returning to the show, it was peculiar when Moffat and Gatiss told BBC, "Ghosts of the past are rising in the lives of Sherlock Holmes and John Watson bringing adventure, romance and terror in their wake. This is the story we've been telling from the beginning. A story about to reach its climax."

What ghosts are coming back? Is anyone ever dead on the show? 

According to Benedict Cumberbatch's words to BBC, "Wait for season 4 will be worth it."

In Holmes shall we trust?