To avoid crossing over via the Machine Room, Lincoln retrieves Walter's original dimension-crossing device, which in this timeline has been acquired by Massive Dynamic.

Peter does not learn until later that Olivia has told Lincoln to discover whether Walternate is behind the appearance of a new class of shapeshifters.

Walternate is aware that these new shapeshifters have started to infiltrate his government, and the only reliable method he has found to detect them is the tazer-device, but that this will not be effective as it is fatal to humans.

Fauxlivia and Lincoln discover the location from where a phone call to one of the drivers was made, and get Broyles' (Lance Reddick) permission to investigate the source.

"Back to Where You've Never Been" was co-written by co-producer Graham Roland and co-executive producer David Fury, while being directed by French director Jeannot Szwarc.

Club gave it an "A-", calling it a "mostly terrific" episode that effectively advanced the season's story, though he noted some confusion in the alternate-reality setup.

[6] Andrew Hanson of the Los Angeles Times highlighted the episode's balance of emotional moments, such as Walter's reflection on his wife's suicide, with plot twists involving Walternate and shape-shifters.