Criminal Minds - Season 4 ... File

: Takes maternity leave to give birth to her son, Henry, and is briefly replaced by Jordan Todd.

: Suffers from injuries following a car bombing in the season premiere, "Mayhem".

Now we see JJ's replacement, Agent Todd, because she's on baby duty. Unsubs: A Criminal Minds Podcast Criminal Minds Season 4 Episode 8: Masterpiece - Tunefind

: Finally confronts his long-lost father in the two-part "Memoriam".