Series regulars Clark Gregg, Ming-Na Wen, Chloe Bennet, and Iain De Caestecker also briefly appear.

The episode was a departure from the norm for the series, focusing on a single character rather than the usual ensemble, and taking place on an alien planet.

The episode was filmed in the Californian desert, with a filtering effect used to make it appear to be night on the planet, as its sun rarely rises.

"4,722 Hours" originally aired on ABC on October 27, 2015, and according to Nielsen Media Research, was watched by 6.40 million viewers within a week of its release.

While out scavenging for food, Simmons sees a metallic reflection in the distance, and follows it to find an old sword and 19th century astronomy equipment.

Realizing that she has entered what Will calls the "No Fly Zone", the area where his fellow astronauts all went before they died, Simmons is soon caught up in another sandstorm—this time, she sees a cloaked figure approaching her and flees back to the cave.

Inspired by the astronomy equipment to use the stars and moons, Simmons deduces that the portal's location is fixed but appears to move due to the planet's rotation.

In September 2015, following the airing of the season's premiere in which the location of the character Jemma Simmons was revealed to be an alien planet, executive producer Jeffrey Bell stated that "at some point we will fully explore what's happened to her".

Series writer and supervising producer Brent Fletcher came up with an idea to split the 4,722 hours into five acts, with each written like the chapter of the book.

[7] In October 2015, Marvel revealed that main cast members Clark Gregg, Ming-Na Wen, Brett Dalton, Chloe Bennet, Iain De Caestecker, Henstridge, Nick Blood, Adrianne Palicki, Henry Simmons, and Luke Mitchell would star as Phil Coulson, Melinda May, Grant Ward, Daisy Johnson, Leo Fitz, Jemma Simmons, Lance Hunter, Bobbi Morse, Alphonso "Mack" Mackenzie, and Lincoln Campbell, respectively.

[2] However, the majority of the cast does not ultimately appear, with only Henstridge and De Caestecker playing notable roles; Whedon said that the others basically had "a week off".

[10] In casting Casey as Daniels, the producers wanted someone who was older than Henstridge, physically unlike De Caestecker, and "doesn't look like [Simmons'] type", to make it less clear that they would end up together.

[7] Filming occurred in a work quarry in Simi Valley and in Northridge, Los Angeles near the Mojave Desert during the day,[11] with director of photography Feliks Parnell using a filtering effect inspired by Mad Max: Fury Road to make it appear to be night time.

[7] Around 22 minutes of extra footage was shot for the episode that had to be cut, including a subplot in which Simmons loses her grandmother's necklace and Daniels finds it for her.

Rather than try and film the episode in complete order, which was "impossible" due to location scheduling needs, the production just tried to avoid changing from one stage to another, and then back again.

[18] Den of Geek's Rob Leane was less positive, praising the "brave decision" to focus on Simmons and Henstridge's performance, while noting the "undeniable similarities" between the episode and The Martian, and panning the introduction of Daniels as "more like a plot device than a real driving force for the episode" and the unwanted introduction of a love-triangle to the series.

Freeman stated, "once the dramatic arc of the episode is established, it takes a fairly standard route ... [but] the performance of Henstridge helps to bring enough emotion to give the storyline the weight that it needs".

[20] Kevin Fitzpatrick at ScreenCrush called the episode "inventive and unexpected" and "a brilliant gamble", praising Henstridge's performance and the "immersive" quality of the episode, especially the investment in Simmons' personal development with Daniels and attempts to escape the planet, which he felt was "only occasionally marred by the required exposition of its more improbable elements".

has given us, and one of the few a viewer with almost no prior knowledge of the show can fully appreciate", and praised the handling of Simmons' and Daniels' relationship, saying that Henstridge and Casey "complement one another marvelously".