Liz infiltrates the blacksite and disarms the signal jammers to call in backup but runs into trouble along the way. The fate of Ressler hangs in the balance as Red tries to bargain with Anslo Garrick. Meanwhile, Tom becomes increasingly worried about Liz' situation and the fate of Red is unknown.

The team goes undercover to pursue the Alchemist, who uses science to transform DNA and who's been assigned to protect a mob informant. Elsewhere, Liz targets an unlikely couple; Tom and Liz's relationship is tested; and Ressler faces a big decision.