Olivia. In the Lab. With the Revolver.

In the episode, Olivia (Anna Torv) investigates a man with a possible connection to her who has the lethal ability to spread cancer by touch.

In Providence, Rhode Island, lawyer Miranda Green (Diane Kruger) takes a lunch meeting with sickly young man James Heath (Omar Metwally).

Olivia (Anna Torv) has a sleepless night owing to her recent discovery that Peter (Joshua Jackson) was abducted from the "Over There" universe by a grief-stricken Walter (John Noble).

In the case, it transpires that victims of attacks similar to Miranda Green’s have been connected to the Cortexiphan trials in Jacksonville, Florida.

Olivia visits Nina Sharp (Blair Brown) at Massive Dynamic's headquarters and demands a full list of the subjects, knowing she herself is one of them.

The episode was written by production staffer Matthew Pitts, a former assistant to series co-creator J. J. Abrams,[2] while former Fringe producer Brad Anderson served as director.

Kruger was in a relationship with star Joshua Jackson at the time, and requested that her part be as a "gooey monster", where her "eyes are popped out" of her head.

[9] The episode contains a deleted scene between Broyles and Olivia discussing the James Heath case, which was available on the second season's DVD as a special feature.

During the episode's first sequence, lawyer Miranda Greene's partner in a car-phone conversation mentions the name "Gorlomi," which was the assumed identity of Brad Pitt's character Aldo Raine in the 2009 movie Inglourious Basterds, also starring Diane Kruger.

Murray appreciated the episode's use of a secret that "eats at people when they can’t bring themselves to air it out", particularly spotlighting the "look of panic" on Walter's face when Olivia and Peter leave his lab.

"This week’s episode stood up as a perfectly comprehensible hour even if you were new to the series, thanks to its medical mystery and fun side-moments such as Walter making brightly colored taffy.

But is [sic] also wove in characters and names from previous episodes — Nick Lane, Nancy Lewis — and raised the tantalizing suggestion that the illness James Heath suffered from might be a malady that’s also afflicting parts of the alternate universe.

"[8] MTV columnist Josh Wigler positively noted "Mysteries of the week are always compelling when they have interplay with the overarching mythology of Fringe, which was exactly the case in tonight's installment.

"[17] The IGN writer praised Walter going back to his old jokes while at the same time possessing "an undercurrent of fear and shame in his personality as he deals with Olivia's knowledge of Peter's secret", but disliked the first half's "slow, procedural" elements as well as the cancer make-up.