WARNING: The following article contains spoilers for The 100 Season 6, Episode 9, "What You Take With You," which premiered this week on The CW.
Despite the dangers on the new, alien world of Sanctum -- and being caught in between the conflict of the planet's two rival factions the Primes and the Children of Gabriel -- most of the returning cast of The 100 has managed to stay alive for much of Season 6.
However, this relative period of safety comes to an abrupt end in the most recent episode of The CW series, with a character that has been a major part of the show since the pilot episode making a heroic sacrifice in an effort to cease the cycle of the Primes possessing generations of willing disciples, killing the consciousness of the original host body.
Kane has had one of the biggest character arcs over the course of the entire post-apocalyptic series, starting out as a stern, unwavering councilman who had sent the eponymous hundred young adults and teenagers to Earth's surface in a desperate effort to rebuild human civilization.
Over the subsequent six seasons, he had gradually grown to become a much more sympathetic character as he arrived on Earth himself, integrating himself with the local society and becoming a strong advocate for peace between the warring factions on Earth, often at the cost of his own physical wellbeing.
After striking up a romance with physician Abby Griffin, Kane had developed a deadly infection that resulted in him being placed in cryosleep for the majority of the season while Abby desperately searched for ways to cure him.
After attempting to use medicinal algae at the start of the season, it became clear to Abby that she would need even more radical methods to keep her love interest alive. This was when she learned of the Primes' technique of transferring their minds into new host bodies, effectively granting themselves a form of immortality.
In order to save Kane, Abby made a deal with the Prime, Simone, to create more Nightblood, the blackened, radioactive resistant blood necessary for the mind transfer to be successful, if they could replicate the process with Kane. The past several seasons had seen Abby make deals with various devils in what she continually lied to herself as a justifiable, greater good and the trend continues into Season 6 with her deal to save Kane.
Despite the misgivings of Raven Reyes, the engineering genius and pilot who had previously been abused by a drug-addicted Abby, Kane's mind is transferred into a new, younger host body. Upon his awakening, Kane is horrified to learn of the lengths Abby went to keep him alive, in particular, that his new form came at the cost of killing the original consciousness within the body. Learning of Abby's plot with Simone and the Primes, Kane teams up with Raven and awakens his old friend Indra to develop a plan to stop this sinister deal from progressing further.
Awakening more survivors from Earth riding in cryosleep aboard the Eligius IV where Simone and Abby are creating new Nightblood, Indra and Raven lead a quick uprising to seize the Nightblood and hold Simone and her followers hostage. As Abby attempts to defuse the situation she is shocked to learn that Kane had been orchestrating the power play... and secretly returned to his original dying body.
As the two lovers share one final tearful goodbye, Kane reminds Abby that she knows the morality behind the Primes' mind transfer is suspect and ejects himself into space with the remaining Nightblood.
Kane had long paid for his past transgressions by standing by his renewed sense of humanity and compassion as he integrated himself with local cultures. While he had found love and solace with Abby, originally a bitter rival, Kane had started Season 6 facing his own mortality and chose to stand and die by his convictions rather than live on at the expense of others.
What his heroic sacrifice may mean for Abby and her future interactions with the Primes has yet to be seen, but it will certainly inform her character for the remainder of the season.
The 100 airs on The CW Tuesdays at 9 p.m. ET/PT. The series stars Eliza Taylor, Paige Turco, Marie Avgeropoulos, Bob Morley, Henry Ian Cusick, Lindsey Morgan, Richard Harmon and Tasya Teles.