Season 4, Episode 21 is It features a major resignation and a high-stakes investigation.
Though technically the finale (spanning episodes 21 and 22), the season 4 conclusion involves a massive secret being revealed. [S4E21] The Last Word
Depending on which show you are referring to, here are the most relevant "papers" or guides: Season 4, Episode 21 is It features a
: "Career Day." A lighter episode involving Claire returning to the workforce, detailed on Wikipedia . [S4E21] The Last Word
: "Asylum" (Part 1 of the S4 finale). You can find technical and plot discussions on Wikipedia .
Entertainment Weekly provides a recap of "Mr. Kaplan: Conclusion," which centers on the "truth" Red is hiding. Other Notable S4E21 Episodes