Walter (John Noble) is struggling with the hallucinations of Peter (Joshua Jackson), but refuses to talk about it to the Fringe team or to his psychologist (William Sadler), fearing they will consider him insane and put him back in the mental institution.
Walter, while examining Aaron, finds that the boy lives with his neighbors, his father having died and his mother being away on business travel in Europe.
Walter races to find non-invasive ways to break the link between Aaron and the organism, ultimately concluding with reluctance that lobotomy may be the only answer.
As Olivia (Anna Torv) and Lincoln (Seth Gabel) prepare to destroy the fungus network by injecting a toxin (provided by Massive Dynamic) into its heart, Walter finds that Aaron has become emotional, fearing that there is no one that cares for him.
[2][3] Because covers of the song have been "slightly altered and reinterpreted" for years, Entertainment Weekly writer Lanford Beard noted its use "seemed [a] particularly on-point metaphor for the cult show's current season.
But I can’t fault Fury and Sapochnik for the many memorable moments and images in this episode: the eerie glow of Gus’ tendrils seen through night-vision goggles; the morgue guy refusing to answer the phone, and ending up frozen and decaying over an exploded corpse; Walter dumping another exploding corpse into a container just in the nick of time; and of course Walter sitting alone in the dark with a hammer and a spike and a book on lobotomization."
Andrew Hanson from the Los Angeles Times expressed uneasiness that the victims were children, and was skeptical that Olivia and Lincoln would have removed their hazmat suits when encountering the center of the fungus.
"[4] Isler did however enjoy the final minutes of the episode, calling it "an uplifting note to a rather depressing story, and for the first time this season it leaves our characters with an explicit purpose and direction.
Club's Noel Murray gave the episode a B−, explaining that while the writers did a "solid job", it was "a big step down from last week's magnificent 'One Night in October'".
[2] He continued, "The problem is that the way the episode plays out requires Walter to save the day by talking Aaron out of the mental/emotional clutches of Gus, which isn't exactly the most visually dynamic climax to an action-adventure show.