When Cat (Kristin Kreuk) is assigned to a new partner by Tess (Nina Lisandrello), she begins to suspect that Bob (guest star Alan Van Sprang) and Carol (guest star Natasha Henstridge) have re-surfaced to separate her from Vincent (Jay Ryan) and hunt them both down.
When King Antoine (guest star Ben Aldridge) threatens to tell Francis (Toby Regbo) of Mary (Adelaide Kane) and Condé’s (Sean Teale) evolving relationship, Francis makes a shocking move.
The journey to the City of Light continues, and Jaha (Isaiah Washington) makes a move that shocks Murphy (guest star Richard Harmon).
Malcolm (John Barrowman) is captured by Ra’s al Ghul (guest star Matt Nable) and taken to Nanda Parbat.
Mary’s (Adelaide Kane) mother (guest star Amy Brenneman) returns to advise Mary that her throne is in jeopardy.
After assigning tasks to each of her friends, Caroline (Candice Accola) attempts to deal with her current situation as reality begins to set in around her.
Clarke (Eliza Taylor) begins to question Lexa’s (guest star Alycia Debnam Carey) leadership decisions.
Malcolm (John Barrowman) puts Oliver (Stephen Amell) and Thea (Willa Holland) in a dangerous situation that lands them on Lian Yu with Oliver’s former enemy, Deathstroke (guest star Manu Bennett).
After the nuclear explosion separates Ronnie (guest star Robbie Amell) and Dr. Stein (guest star Victor Garber), Barry (Grant Gustin) and the team believe both men are safe.
As Mary (Adelaide Kane) and Francis (Toby Regbo) investigate who was behind the poisoning of King Henry (Alan Van Sprang), they unearth secrets of the past which force Mary to confront her feelings for Condé (Sean Teale) as she attempts to move forward.