It was written by head writer Eric Martin and Katharyn Blair, and directed by Aaron Moorhead and Justin Benson.

Tom Hiddleston reprises his role as Loki from the film series, starring alongside Sophia Di Martino (Sylvie), Gugu Mbatha-Raw (Renslayer), Wunmi Mosaku (Hunter B-15), Eugene Cordero, Tara Strong (Miss Minutes), Neil Ellice, Jonathan Majors, and Owen Wilson (Mobius) reprising their roles from the first season, alongside Rafael Casal, Kate Dickie, Liz Carr, and Ke Huy Quan.

After He Who Remains' variant Victor Timely arrives at TVA headquarters, he is asked by Loki and Mobius to assist in fixing the Temporal Loom, which is reaching catastrophic failure due to the inability to handle branching timelines.

Hunter B-15 visits the detained group of General Dox, her loyalists, and Brad Wolfe, leaving them after giving them an offer to work together to defend the TVA.

However, Timely is instantly spaghettified upon exposure to the Loom's increased temporal radiation, leaving the Throughput Multiplier unused.

[6] The fourth episode, titled "Heart of the TVA",[citation needed] was written by Martin and Katharyn Blair,[7] and was released on Disney+ on October 26, 2023.

[8] Eric Martin had felt the episode was the "pivot" for Loki's story and that the season's ending would be complex rather than being a "straight line that we expect".

Ultimately, the episode served as a continuation for Martin's overall theme for the season, which was focusing on power vacuums and dictatorships, intending to push the characters and TVA to their "breaking points" and examine if reform was possible.

[11] The episode stars Tom Hiddleston as Loki, Sophia Di Martino as Sylvie, Gugu Mbatha-Raw as Ravonna Renslayer, Wunmi Mosaku as Hunter B-15, Eugene Cordero as Casey, Rafael Casal as Hunter X-5 / Brad Wolfe, Tara Strong as Miss Minutes, Kate Dickie as General Dox, Liz Carr as Judge Gamble, Neil Ellice as Hunter D-90, Jonathan Majors as Victor Timely, Ke Huy Quan as Ouroboros, and Owen Wilson as Mobius M.

[12]: 44:45–45:17 Filming took place at Pinewood Studios in the United Kingdom,[13] with Benson and Moorhead directing, and Isaac Bauman serving as cinematographer.

[4]: 2, 19  Visual effects for the episode were created by Trixter, Rising Sun Pictures, FuseFX, Framestore, Cantina Creative, and Lola VFX.

For the scene, the crew directed Tom Hiddleston to look at an array of 24 LED panels that was arranged outside of the temporal core control room.

However, Hughes felt the ending was the best part of the episode, writing that it is "a hilarious subversion of Loki's more traditional storytelling impulses, which can sometimes fall back on gung-ho optimism".

[23] Like Adlakha, Gizmodo's Sabina Graves also felt that the ending's implications were trivialized due to the introduction of the multiverse and if there is "no consequence to MCU at large, allegedly?"