SPOILER WARNING: This article contains major spoilers for "Collision Course (Part 1)," the latest episode of Agents of S.H.I.E.L.D.

Agents of S.H.I.E.L.D. is on the brink of answering a seasons-long mystery. In "Collision Course (Part 1)," the latest episode, the series drew even closer to explaining the monoliths, their purpose and where they came from.

As Fitz and Simmons traveled back to Earth with their new friend Izel, she provided a little insight on her background and the artifacts she seeks. "I envy that you're almost home. I'm afraid I'll never see mine again," she told them.

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Simmons changed the subject by asking for more information about Izel's lost artifacts, in the hopes they could help her track them down. "The Dialas. They're made of stone, and they were stolen from my world millennia ago," she explained. "They can create, move beings through space and time..."

The Earth-bound pair immediately recognized that description. Fitz suggested the monoliths, not knowing they had been destroyed in Season 5. Simmons steered the conversation away from them and told Izel she heard a rumor they were on Chronyca-2, the Chronicom home world. That's when Izel offered a lie of her own.

"I'd heard the same. That's why I went to their homeworld, but I was attacked and my crew was killed. The whole planet was destroyed. I'm afraid the same might happen to Earth if I don't find those artifacts," she said. Of course, Sarge told a different version of that story to Daisy: he and his crew were unable to stop her before she unleashed the Shrike on the planet, which led to its death.

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Izel also explained why the monoliths exist. "They were created to connect life together, but there's someone who had no interest in that. He murdered my crew, and he won't stop until he eliminates me," she revealed. Simmons asked why this person, who is clearly Sarge, wants Izel dead. Izel simply replied, "Because I know the truth about him. I know what he really is."

Later in the episode, Dr. Marcus Benson made some discoveries about Izel on his own and sent his findings to Director Alphonso "Mack" Mackenzie. "You ever hear the name Izel? It keeps popping up in this research, something from Incan mythology," he asked Elena "Yo-Yo" Rodriguez.

When Yo-Yo came up blank, he continued, "It's an ancient entity. It could be one of their gods -- a demon, a fallen angel, an alien overlord, I don't know. Whatever she was, thousands of years ago, she escaped from a realm of fear and darkness... After she escaped, she tried to track down relics from our realm called the Dialas to regain power."

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"She left a path of destruction wherever she went, destroying worlds looking for them," he added. When Yo-Yo asked why, Mack replied, "Well, that's the question we need to answer."

Indeed, that will be the question for upcoming episodes of the season. Until then, though, "Collision Course (Part 1)" provided some valuable clues. For one, the monoliths are not native to Earth -- and neither is Izel, though she has been to the planet before, at least according to ancient Incan legend. For another, they were created to connect people, not to harm them. Finally, she is willing to kill to get them, and she's got a scorched Earth policy to match.

Of course, some of this information depends on how honest Izel has been with Fitz and Simmons. After all, she has already proven herself to be an unreliable narrator, per the lie about the destruction of Chronyca-2. However, the best lies are couched in the truth, and hopefully that is the case with Izel's story here.

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Agents of S.H.I.E.L.D.'s first monolith was introduced in the second episode of Season 3. The space monolith debuted in a flashback to 1839 England, where Hydra sent one poor soul in accordance with an ancient tradition. It turned out the monolith was a gateway to Maveth, the planet Hive destroyed. Phil Coulson and his team eventually used it to rescue Simmons from space.

A second monolith debuted in the Season 5 premiere. This monolith moved the team through time instead of space, dropping them off in the year 2091. Here, they learned of the planet's destruction and used this knowledge of the future to prevent it from happening in their present.

Halfway through Season 5, a third monolith was introduced. The purpose and abilities of this monolith are still unknown. However, Benson came up with a theory in "The Other Thing," Season 6's fifth episode. "Well, if monoliths control space and time, maybe these control life and death," he proposed after a dead Shrike developed the same molecular properties as the monoliths.

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Like Simmons mentioned, all three monoliths were destroyed in the Season 5 episode "The Real Deal." The explosion, triggered by a Kree orb, tore a hole in space-time; this tear opened their reality up to the Fear Dimension, which let all sorts of their nightmares take physical form. Considering Izel "escaped from a realm of fear and darkness," the explosion may have released her from this Fear Dimension.

Since the other monoliths control time and space, it's entirely feasible she was propelled out of the Fear Dimension -- and dropped anytime and anywhere, with a universe full of possibilities. Perhaps this is where Sarge originated too. Coulson, who knew he was dying, confronted the Fear Dimension head-on; perhaps the specter of himself that he faced was also freed from the Fear Dimension, creating Sarge.

Marvel's Agents of S.H.I.E.L.D. airs Fridays at 8 pm ET/PT on ABC. The series stars Ming-Na Wen, Chloe Bennet, Henry Simmons, Iain De Caestecker, Natalia Cordova-Buckley, Elizabeth Henstridge and Clark Gregg.

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