Marvel's Agents of S.H.I.E.L.D. reinvents itself every season, and season 5's deep dive into full-on science fiction is its most ambitious yet. Thrusting Agent Coulson and his team into the future - a world where the Earth has been destroyed and S.H.I.E.L.D. is prophesied to save the world - season 5 has been gradually peeling back the layers to reveal an even more intricately complex time travel storyline than expected.
Season 5's timeline at first seemed straightforward. The S.H.I.E.L.D. team (minus Fitz, who cryogenically froze himself and joined them later) were kidnapped from a diner at the conclusion of season 4. They were transported 78 years into the future by a group called the True Believers, using a Kree Monolith controlled by an isochronus cyclotron. S.H.I.E.L.D. found themselves on a space station called the Lighthouse, which survived the destruction of Earth. The Lighthouse, and the ragtag remains of humanity within, were under the dominion of the Kree. The Kree's leader, Kasius, ran a business of sorts: he created Inhumans to fight in gladiator matches and to sell to the highest bidder.
As for how Earth was destroyed, all signs point to Daisy Johnson as the culprit. To the Kree and to many of the human survivors, Daisy is known as Quake, the Destroyer of Worlds. Sometime in 2018, Quake is believed to have used her powers to tear the Earth to pieces. Meanwhile, the True Believers, a group of survivors who adhere to the prophecies of an Inhuman seer named Robin Hinton, brought S.H.I.E.L.D. to the future in an attempt to remove them from the timeline and to eliminate Daisy Johnson, thinking killing her would prevent the destruction of Earth.
In the episode 'The Last Day,' the Believers, led by Voss, failed to kill Daisy. Meanwhile, we saw scenes from a new timeline where some of the Agents did manage to leave the future and travel back to 2018, yet still failed to prevent Earth's destruction.
It's easy to see how all of these time travel shenanigans can make your head spin. Thankfully, Reddit user tbeazley4247 created a useful infographic (above). With it, we can sort out everything known so far about the twisty Agents of S.H.I.E.L.D. season 5 timeline:
2017 - 2091
Season 5 began in 2017, picking up immediately at the conclusion of season 4. Enoch, a Chronicom anthropologist working with the True Believers, led a team into an LA diner to kidnap Phil Coulson, Melinda May, Daisy Johnson, Mac Mackenzie, and Yo-Yo Rodriguez, leaving Leopold Fitz behind. (This gathering at the diner is the last time the Agents of S.H.I.E.L.D. are publicly seen together.) Coulson and company (minus Fitz) were brought aboard the Lighthouse in 2091.
With the exception of 'Rewind', the episode detailing how Fitz, with the help of former Agent Lance Hunter, met Enoch and a young Robin Hinton and ultimately cryogenically froze himself to join his friends in the future, and the flashbacks shown in 'The Last Day' (see below), all of season 5's events have taken place in 2091.
At some point in 2018, Earth is destroyed, which is believed to be the fault of Daisy Johnson. Footage shown in the season premiere 'Orientation, Part 2' and in 'The Last Day' place Daisy in Los Angeles not long before the planet is quaked apart. One piece of footage shows Daisy outside the Zephyr as it takes off, presumably with May, Simmons, Robin, and others en route to safety in the Lighthouse. Daisy is seen walking out frame after the Zephyr launches. She is never seen again. An earthquake measuring 12.8 on the Richter scale destroys the Earth. (However, this may also be related to the discovery of Gravitonium on board the Lighthouse.)
Surviving a gravity storm caused by Earth's destruction, May crashes the Zephyr to the safety of the Lighthouse. A large of group of people have taken refuge inside. By this point, Robin Hinton's mother Polly has already died; May becomes Robin's caretaker and new mother-figure. Fitz and Yo-Yo are also in the Lighthouse and survive the cataclysm. Not present are Coulson and Mac; it has not yet been revealed if they never returned to 2018 or if they died when Earth was destroyed.
The Lighthouse is now floating in space, surrounded by asteroids which are debris of the Earth. At some point between 2018 and 2022, the Kree arrive to 'save' humanity by taking control of the Lighthouse and enslaving the remaining members of the human race, eliminating their history and remaining forms of books and media. Kasius purchases Vrellnexian roaches as a form of security and punishment for any rebellious humans. Yo-Yo goes to war with the Kree over the fate of Mac; she is presumably killed as a result.
By 2022, Fitz and Simmons begin to design the schematics for the isochronus cyclotron that will control the Kree Monolith but will be unable to complete it. Fitz also has come to believe that time is fixed and posits the idea that they have made more than one attempt to alter the timeline of Earth's destruction and have failed each time. Further agitating Fitz is the knowledge that Jemma will always die, according to Robin's visions.
A fan theory has formed around who Deke's mother is. Deke's father is Owen Shaw, one of the True Believers, who completed construction of the isochronus cyclotron before he died in the late 2080s. Some fans believe Deke's mother is the daughter of Fitz and Simmons, who married on board the Lighthouse. Deke's mother is killed by the Kree at some point in the 2070s. Owen is sent to the surface and is killed by the Vrellnexians before the Agents of S.H.I.E.L.D. successfully arrive in 2091. However, a piece of the Kree Monolith was in Deke's mother's possession and passed to Owen.
At some point also, the Zephyr, containing members of the True Believers including an elderly Robin Hinton and Voss, escapes the Lighthouse and takes refuge on the largest remaining debris chunk of Earth. Meanwhile, Deke (further fueling speculation he's a scion of FitzSimmons) managed to reconstruct the Framework technology, starting a business where he sells virtual reality escape to the people on board the Lighthouse. Deke's acumen to understand and rebuild the Framework lends credence to the idea he's related to Fitz and Simmons.
This is where the bulk of season 5 takes place. The Agents arrive on the Lighthouse. Simmons becomes a slave of Kasius. May is separated from her friends. Deke betrays Daisy to Kasius, who enslaves her as the Destroyer of Worlds. Coulson, Yo-Yo, and Mac meet Tess and Flint. Tess dies after Flint becomes an Inhuman. Meanwhile, Fitz is awakened from cryo-freeze by Enoch and, posing as a wealthy marauder, helps Simmons and Daisy escape Kasius. The Agents of S.H.I.E.L.D. are briefly reunited. Simmons and Yo-Yo remain on the Lighthouse with Flint to help fight the Kree. Coulson, Daisy, Deke, and FitzSimmons escape to the surface and are brought to the Zephyr, where they are reunited with May and meet Voss and the elderly Robin Hinton. Voss and the True Believers try to kill Daisy, but Robin dies instead.
As much as we know right now, many huge questions remain, including the exact circumstances of how Earth really was destroyed, how the Agents are able to find the enough of the Kree Monolith to go back in time to 2018, what happens to Coulson and Mac, and how Flint - a young Inhuman with the power to move rocks with his mind - fits into all of this. There's definitely a master plan Agents of S.H.I.E.L.D. is expertly executing, as season 5 earns S.H.I.E.L.D.'s position as the best reviewed Marvel television series.
Marvel's Agents of S.H.I.E.L.D. airs Fridays @ 9pm ET on ABC.