Season 1 Episode 4
"Bone May Rot"
Matters of trust come to a head while while the team tries to prevent a global pandemic at the CDC; test results put Jane's identity in question.
In a complete lapse of judgment, Patterson leaves photos of Jane's tattoos lying around her house where her boyfriend David can see them; however, when he gets a hit on a tattoo with the CDC logo, she has to share the discovery with the team. Sensing the impropriety, Mayfair uses it to put Patterson off the track of the Guerrero file.
A visit to the CDC's lab requires ultraviolet decontamination, which exposes a series of numbers tattooed on Jane's face in invisible ink. Those numbers correspond to vials of the world's most virulent diseases, which have gone missing. It turns out the CDC's director and her assistant are embroiled in a misguided scheme to save the world by destroying it by causing a global pandemic. The team rushes to the Manhattan Cruise Terminal, where they find a suitcase set to disperse a toxic cloud. When Weller is left alone to guard the contained device, Jane senses a threat and rushes in to save his life and countless others.
At the end of a tough day, there are three new factors in the mix: Zapata has $40K in gambling debts with three days to pay up or else; CIA Deputy Director Carter wants to interrogate Jane and Mayfair is the only thing standing in his way; and Patterson has tested Jane's tooth to find the presence of an isotope that indicates she was born in sub-Saharan Africa. Thus she cannot be Taylor Shaw, who was born in Pennsylvania - a conclusion Weller refuses to accept.