It’s going to need two posts, because I’m capped at 7500 words.
Season 1:
Brief explanations of humanity up until the beginning of colonization, briefly touch on Cole for an episode or two, show fresh look into the Orion program, specifically following Johnson and his perspective of it and the insurrection. Midseason ends with The conscription of the 150 children and the beginning of the Spartan II program. John, Linda, Kelly, Fred, Sam, Kurt, Will, and many other IIs are introduced, though only the main three (Sam, Kelly, John) are given major screen time. Back half is training, a continually worsening civil war, and strange anomalies (hints of Covenant). Season Finale is the Spartan IIs graduating, with the last scene of them being the funeral for those that died in augmentation, meanwhile Johnson fails to take a shot on Tribute resulting in a lot of people losing their lives. (These events don’t take plae perfectly together, but they’re close enough to weave together, even if it means changing a few elements around)
Season 2:
Johnson is sent to Harvest ostensibly to help the planet with CMA training. The newly augmented Spartan IIs show massive improvements. Johnson’s involvement on Harvest becomes a lot more complex. Midseason ends with the capture of Watts by the Spartan IIs and Johnson starting the op that ultimately ends in the destruction of minor transgression, but the Covenant aren’t revealed until the next episode. Second half involves the Spartan IIs deploying in several ops as they get close to Chi Ceti IV, before ending with Sam’s death. Meanwhile Johnson pretty much plays out the rest of Contact Harvest, the planet is partially glassed and we’re introduced to Tartarus, the three high prophets, and maybe even Thel makes a cameo in the last scene of the season finale. The Covenant and their great journey is hinted at, but it is never revealed as to what exactly it is.
Season 3:
Harvest Campaign, reintroduces Cole and Keyes (who would have briefly appeared in season 1). Johnson’s perspective of the early Human-Covenant war. The Spartan IIs first ground encounter with the Covenant, and the introduction, briefly, of both Hood, Cutter, and The Spirit of Fire. Midseason ends with the Harvest campaign basically being over, madrigal being glassed, and the survivors beginning to form the rubble. Last half shows the final battles of Harvest, The Spirit of Fire and its crew’s perspective on the final battles around Harvest, introducing characters like Anders and Forge and the investigation of Forerunner technology. The Spartan IIs continuing to jump from system to system fighting like hell, before finally ending in preparation for the Battle of Arcadia. Alice, Douglas and Jerome are introduced as minor characters. Lots of fighting and space battles in this season. Johnson is faded out to a minor character this season as well as Keyes. Kurt begins to become more featured throughout this season, and is abducted by ONI, who are really introduced for the first time, near the end of the season. During this and the next season, we see glimpses of the Covenant, with minor arcs for Thel and Tartarus, as well as some insight into Covenant leadership. Buck Cameo.
Season 4:
Battle of Arcadia crosses over both the Spirit of Fire’s arc with the Spartan IIs arc. The majority of Spartan IIs go on and continue to participate in several operations around the galaxy in the continued efforts to stop the Covenant. Three go with the Spirit of Fire, who’s arc concludes with the mid-season finale with the death of Forge and Spirit of Fire being lost with all hands. Kurt, who only played a minor role in the last season, will be featured at the last half of season 4, replacing SoF. Johnson will briefly be featured. The Season will introduce the training of the S-IIIs all the way to the last op of Alpha Company. Cameo for Jun, Carter, Emile, and Thom as kids in Alpha. Keyes will briefly appear towards the end of the season, preparing him for his arc next season.
Season 5:
Keyes is selected to be a part of an effort for the Midsummer Night. Kurt recovers from the damage of losing Alpha company. Deeper machinations of the Covenant reveal that humanity isn’t their primary focus. The Rubble is reintroduced, and plays an important role until it is destroyed in the midseason finale. Grey team briefly appears, and Thel’s backstory is given a lot more depth. The Outer colonies are falling. The Spartan IIs, who are featured less and less as they fade into myth, are breifly featured in an arc that ends with Kelly questioning hope as Jericho VII falls and John watches it get glassed. Kurt trains the newly conscripted Beta spartans vowing not to let the same mistakes happen again.
Season 6:
Keyes continues to fight, even as the outer colonies continue to be decimated. The Spartan IIs suffer a few casualties. The Beta IIIs are trained. We’re introduced to Tom, Lucy, Adam, Min, Catherine, and several other members of Beta company. Cole’s fleet continue to barely hold together, winning victories at high prices. Tartarus becomes Truth’s right hand, and we’re introduced to a member of the Vadam clan (not Thel). The two work side by side on several important missions. Midseason ends with Beta graduating and preparing for their first, deployment, and Tartarus, by order of Truth, killing Vadam (not Thel). Truth then reveals a massive fleet, and its movements, which will lead it to clash directly with Cole’s. Back half of the season involves a few minor ops for Beta Company, Tartarus ascending to the leadership of the brutes, Blue team briefly being involved in a few ops. Operation TORPEDO goes live, with Catherine oddly missing. Cole makes a last stand, turning Viperdae into a miniature nova. Beta company is wiped out, except for Tom and Lucy, but TORPEDO is considered a success. Lucy loses her voice. Tom privately breaks down, and is found by Kurt, who is also devastated at the loss. Kurt breaks protocol and indoctrination by showing Tom that Catherine was still alive.
A montage of scenes from the war play. Johnson is angrily killing a group of grunts, lit cigar burning in his mouth, Buck is trying to revive a fallen comrade who is severely burned and has a hole in his midsection, with no success. Thel leads a squad of elites while they tear through a line of marines, the last one alive is left wounded and holds a picture of his daughter before looking up at Thel, who cuts him down. Tartarus is seen striding with confidence as his pack races through a crowded city street, killing civilians with their hands and spikers in a display of savagery. A viewport from space shows a planet burning as Truth’s smiling reflection is seen. Kurt reveals to Tom that several IIIs from Alpha and Gamma were pulled from their companies to work on a special program. Tom Asks why and a the last scene of the montage shows Blue Team, battle scarred but still fighting in a heavily destroyed city, surrounded by recently slain Covenant. It is raining, and the rain washes the blood away, where it mixes with red. Thousands of human corpses are seen littering the city.