Episode 4, "Homecoming," transports the audience back in time, revealing a younger John, alias Master Chief, in his Spartan training days, portrayed by the young actor Casper Knopf. As a rebellious youth, he has repeatedly attempted to escape, landing him in trouble numerous times. Dr. Halsey, in her younger avatar portrayed by Natascha McElhone, offers words of encouragement, urging John to persevere in his Spartan training. His heart, however, remains fixated on returning to his childhood home, Eridanus II, where vague memories of his upbringing persist. Dr. Halsey implores him, explaining that he is not merely a Spartan, but the key to humanity's survival, and that his place is here, in this training.
In the present timeline, Pablo Schreiber steps into the shoes of the adult John, who is now on a journey to Eridanus II, accompanied by Dr. Halsey and Cortana (Jen Taylor). He holds a firm belief that the artifact discovered on Madrigal is merely a fragment of a larger puzzle, and that the core relic lies buried on his homeworld. His fractured memories gradually resurface, revealing visions of his younger self sketching both the Madrigal talisman and an even grander entity.
Meanwhile, Kwan (Yerin Ha) and Soren (Bokeem Woodbine) have returned to Madrigal, determined to liberate Kwan's planet from the tyrannical clutches of Vinsher (Burn Gorman). The new Madrigal, under Vinsher's iron fist, stands in stark contrast to the democratic and communal spirit of the planet shown in the pilot episode, prior to the Covenant invasion. Once a beacon of democracy and community, Madrigal now trembles under Vinsher's reign of fear and brutality.
The citizens of Madrigal gather for a vigil to honor Kwan's father, providing her with an opportunity to seek out the generals who once served alongside him. Kwan learns with horror that Vinsher has executed all the generals, save for Agatha (Nila Aalia), leading her to believe that Agatha now leads the rebellion. The solemn vigil is abruptly shattered by Vinsher's security forces, who launch a violent attack on the gathered crowd.
Kwan and Soren manage to flee the chaos, but their presence is not unnoticed. Vinsher summons his associate Franco (Angie Cepeda) with a sinister mission - to silently assassinate Kwan, lest she become a martyr. Kwan finds refuge with her aunt, where she uncovers startling revelations about her father that shatter the idealized image she had held of him. Years ago, her father had encountered mystics in the desert, who revealed a profound reason for the Ha family's placement on Madrigal. Their reunion is cut short as Franco strikes, but Soren valiantly fights her off.
Back at the United Nations Space Command (UNSC) headquarters, Spartan Silver Team member Kai (Kate Kennedy) follows in Master Chief's footsteps, removing the pellet from her back. Kai and the rest of the Silver Team are summoned by Miranda Keyes (Olive Gray), who wants to ascertain if any of the other Spartans can elicit the same mysterious response as John when they touch the Madrigal artifact. However, to their disappointment, Kai and the other Silver Team members fail to invoke the relic's glow.
However, unexpectedly, they emerged as a hidden wellspring of Covenant knowledge for Miranda. Years had passed since she embarked on her endeavor to compile a dictionary of the Covenant's enigmatic language, yet she never sought the Spartans' assistance, despite their extensive interactions with the Covenant. Kai and Miranda revisited the archived footage from the initial Madrigal expedition, piecing together the Covenant's words to reveal their meaning: "sacred ring," a reference to the mysterious relic. Kai christened it a "halo."
On Eridanus II, John embarked on a personal excavation, both literal and figurative. Buried deep within the woods, nestled near his childhood home, was a forgotten treasure trove: a box containing drawings from his youthful hands. The team delved into the decaying remnants of John's former abode, and Cortana conjured a vision of its former glory from John's recollections.
Through these reconstructed memories, John decoded the enigmatic drawings, piecing together snippets of his forgotten past. He witnessed himself as a young lad wandering through the woods, heading toward a shadowy cave. In his memories, young John's hand brushed against an unseen artifact, which glowed a brilliant green before he returned to the safety of his home. There, he spied his younger self engaging in a game with Dr. Halsey. As she prepared to depart, she inquired if she might see John again and if their encounters could remain a secret between them.
Over the course of the initial four episodes, HALO has posed an array of intriguing questions, yet offered scant answers. While some mysteries are crucial to sustaining the narrative's suspense, the profusion of unknowns has begun to weigh heavily. Even without Makee (Charlie Murphy) and the Covenant's presence in this episode, the show struggled to progress in a meaningful manner. While the audience now knows that the Madrigal relic is a "halo," for those unfamiliar with the show's context, this revelation remains largely meaningless.
The show's decision to embark on a parallel journey of liberation from the UNSC for Kai, mirroring Master Chief's path, seems superfluous. What initially seemed like a narrative centered on the dynamic between Kwan and John has broadened, introducing new characters with each episode. While their intention to flesh out these new characters is admirable, it has become increasingly cumbersome. Before introducing fresh faces, planets, and conflicts, the audience needs to perceive tangible progress with the characters that first captivated their attention.
