In "Blindspot" Season 1, Episode 3 "Eight Slim Grins," FBI Agent Kurt Weller (Sullivan Stapleton) discovered via a DNA test that Jane Doe (Jaimie Alexander) is his childhood friend Taylor Shaw who was abducted 25 years earlier, but the information is not enough to explain the puzzle of tattoos on her body.

While Shaw does not remember being abducted as a child, the memory is fresh in Weller's mind.

Weller explained that he searched for Shaw everywhere. He even blamed himself because he thought she was dead.

The new revelation will bring Weller and Shaw closer.

In Episode 4 "Bone May Rot," Shaw officially joins Weller's FBI team. Bethany Mayfair (Marianne Jean-Baptiste) agrees to give her a gun.

The episode will focus on a new case at the Center for Disease Control (CDC). While at the CDC, Patterson (Ashley Johnson) and her tattoo expert boyfriend David (Joe Dinicol) discover a hidden meaning of one of Shaw's tattoos that uncovers a plot that could result in a global catastrophe.

In the trailer, the FBI team discovers a series of number in a tattoo that corresponds with an infectious disease. They later find vials of Ebola missing from a laboratory. They race to stop an outbreak, and it triggers a memory in Shaw that explains how it all started.

In the previous episode, robber Casey Robek (Michael Rogers) whispered the word "Orion" in Shaw's ear before he died. In "Bone May Rot," it's revealed that operation "Daylight" also as deep links to her erased past.

Series creator Martin Gero teased on Monday that "Daylight" is a "bigger problem" than Orion.

"Nothing is as straight ahead as it seems. Even if she is Taylor Shaw, where has she been for the past 25 years? What happened to her and why? It's only the beginning of the mystery and not the end," Gero told Variety.

Watch "Blindspot" Season 1, Episode 4 "Bone May Rot" on Monday, Oct. 12, at 10 p.m. ET on NBC.

Do you think Shaw and Weller will have a closer relationship now that it has been revealed they were childhood friends? Any idea where Shaw may have been in the past 25 years? Share your thoughts in the comment section below.