Emily Byrne struggles to make sense of her time in captivity and her tumultuous past. Meanwhile, a deadly terrorist attack rocks the heart of Boston.

Stunned by new revelations from her past, Emily intensifies her search for the truth. Tensions mount at the FBI as Nick and Julianne race to profile the Federal Annex terrorist.

Reeling from a shocking loss, Emily returns to the FBI to get answers. Meanwhile, Nick and Julianne fear the terrorist may be ramping up for his next attack.