Kate Williams was a Russian spy living in the U.S. posing as a 5th grade teacher.

Kate arrived to America when she was a teenager under a fake ID, where she married Nathan Williams with whom lived for ten years until her death.

The arch tattoo on Jane's left arm, led David Wagner to discover a code book Kate and other Russian spies used to communicate. Knowing that the book was compromised, and believing David was an FBI agent, Kate killed him in an alley with the glass from a broken bottle.