For those who have doubts about the chemistry between Ichabod Crane (Tom Mison) and Diana (Janina Gavinkar), the latest promotional still from "Sleepy Hollow" season 4 could help.

The image, exclusively released by TV Line, shows the two side by side as they work on a case. The duo looks confused as they stood in a mysterious room filled with books.

In the "Sleepy Hollow" season 4 photo, Ichabod appears to be looking at someone unseen while Diana examines the items around them, looking like she is bewildered about what she sees.

As revealed before, Diana will replace Abbie Mills (Nicole Beharie) in "Sleepy Hollow" season 4. Although the Second Witness is gone, the series will show what happens without her around.

The new season will see Ichabod search for a new Witness with a brand new team. This mission will bring him all the way to Washington, D.C., where he will meet and form a new group, and a motley one at that.

Abbie's death and the search for the new Witness will bring Ichabod and Abbie's sister, Jenny (Lyndie Greenwood), closer together in "Sleepy Hollow" season 4, bordering on the same feeling of loss.

The two will, in some ways, "rely on each other" and will be more involved in missions in the new season of the hit series, Greenwood revealed to The Mary Sue at the New York Comic-Con (NYCC).

Although Abbie is no more, she will be the vein of "Sleepy Hollow" season 4 and the events that will happen there. In fact, Ichabod dealing with her death is what will help him and Diana get together as a tandem.

Diana has lost someone important to her, a feeling that Ichabod is now all too familiar about. This will open up to a rich relationship between them as partners.

"Sleepy Hollow" season 4 will premiere next year on FOX.