MAN IN THE MIDDLE

There is one inflection point between the island and sideways story arcs. People believe it is Desmond, but the real man in the middle is a background character.

This comes about in reviewing a minor detail in the series. The flight manifest contained the names of all the passengers who flew on Flight 815.  The manifest was part of the papers and materials kept by Sawyer in his stash shortly after the survivors started to build camp.

The earliest known time that the mid-section survivors were in possession of the manifest was day 5 - Sunday, September 26th, 2004, during the burning of the plane. It then went into Sawyer's possession for approximately eleven days before passing to Hurley on Day 16.

Hurley used the manifest in order to make a census of everyone on the beach and in the caves.  He asked everyone for his name, place of residence, and the reason he was in Australia to compile the census.  It was during this process, Hurley found that Ethan Rom was not a passenger on the plane, but an Other.

Lostpedia states that only a few people have actually seen the manifest:

Locke knew Hurley and Sawyer's real names (Hugo Reyes and James Ford) from the manifest.

Sawyer had access to the manifest since it was part of his stash.

Hurley used the manifest to create his census of survivors.

And co-pilot Frank Lapidus claimed he had memorialized the entire 815 manifest so he was able to identify Juliet as not being a passenger. How Frank would have received a copy of the manifest (which is created at the gate through boarding passes) is unknown, but a telling bit of information.

In the flash sideways Flight 815, pilot Seth Norris is listed instead of Frank. Which means some details of the original flight were the same. But the  manifest was slightly different, with some characters such as Desmond,  who were not on the plane originally, were on it in the flash sideways. Other passengers were seated differently or missing altogether.
 
After having some realization about this world, Desmond asked his limo driver to get him a copy of the manifest so he could show the other passengers something. Desmond was later seen seeking out various passengers of Flight 815 and manipulating their circumstances to trigger an "awakening"  though it is unclear to what extent he consulted the manifest to accomplish his goal.

What was the cosmic bridge between the island and the sideways plane manifests?

It could be the knowledge of Frank, who is the only character to leave the island more than twice, and the fact that Ajira 316 actually made it off the island with Desmond on it.

Lapidus is a Biblical name derived from the Latin word lapideus, meaning "made of stone."

So was alcoholic, depressed pilot Frank the foundation stone on which the series can be connected?

Frank, as a character, does not get a lot of credit for being independent, resourceful, dynamic, skilled and perceptive. He knew the evil intentions of the freighter crew from day one. He knew something was wrong in the whole disappearing Flight 815 scandal. In some respects, he was the one who had a clear understanding that people and events were being manipulated, so he rode the wave of the deceptions to find his answers. As a pragmatic person, he survived the various dangers on and off the island. And when he found the 815ers on his Ajira flight, he deadpanned that he was not getting to his scheduled destination.

Or was he?  In some respects, Frank represents an guardian angel for some of the 815ers. Through guilt or heavenly redemption, he literally "saves" several people, including Kate twice. He was the man in the middle of the action, but not swept away by it.

By Frank getting Desmond off the island had to have changed the alternative time line to place Desmond on sideways Flight 815. This is the most dramatic change in the sideways manifest, as it creates the path for Desmond to remember and reunite the island memories to their souls. So Desmond takes on the role of an underworld ferryman or priest, to get his charges through judgment and paradise. 

PASSAGES

There are numerous passages during one's life. There is the physical passage to birth. Then there is the passage from dependent baby to exploring child. Then there is the transition from child to adult. And the final transformation from adult to old age.

Literature is filled with symbolic passages marking life's key events.

The journey through life is depicted as travel, a voyage, a quest, a road to hoe.

At death, is it symbolized in various forms but takes on the elements of travel to the next level existence, heaven. In ancient times, there was the story of the dead being ferried across the River Styx to hell for judgment. In modern times, in movies like Defending Your Life, souls are sorted by various passenger trains. Some evidence suggests that in near death experiences, people see a bright, white light in a tunnel. They get a sense of wanting to follow the light.

Once one reaches the travel sorting station, there is usually a test or continuation of the journey. A weighing of the heart. A defense of good versus evil behavior. Sins judged against moral achievements.

These passages represent a purification of one's spirit. This cleansing is to be done so only "worthy" souls can join in external paradise. Most people believe that one will have a second or third chance to become "worthy" of everlasting life.

All major religions have some teachings about the passage of a person's life force after death. It may be the foundation for hope in the present and the future. The cynical believe that it is merely a means to control unruly populations. There gets to a point throughout history that people would rather take the unknown passage of death than live in the poverty, war, disease or pain of their culture or society.

There is no question that the main characters of LOST had many passages to make during the series. There is a question of whether the whole LOST series was merely a dress rehearsal for the real passage in the sideways after life. Whether the characters were in a island purgatory or human beings transported to a spiritual world, they were given the opportunity to change, make amends, release regrets, and cleanse their sins. Whether they made good on their second chances is highly questionable.

A KEY

How immortal beings such as Jacob or the smoke monster (MIB/Flocke) could have become moral (an apparent requirement in order to "leave" the island existence) is unknown.

But here is a new theory I thought may explain it. It merges a couple of given facts such as the Numbers and Jacob's authority over the island.

MIB was locked on the island's time and space. It could not escape. Jacob was the island guardian, which also could be called a jailor. Jailor's have the keys to the prisoner's cells. Jacob could be considered a jailor to MIB.

The importance of Jacob's numbering system should not be underestimated. It went through the entire series. It was the ultimate clue. Yes, it represented the candidates, but it had to represent more than that because there were more than one hundred prior candidates who did not achieve what either Jacob or MIB desired: escape. One would hope that the candidate numbers would have more meaning than just being numbers.

The numbered candidates could symbolically represent parts of a lock's tumblers, the pieces of metal that move when the proper key is inserted to open the mechanism. Now, if Jacob numbers his candidates, it is either Jacob or the island automatically sets the island's "locking mechanism." The island itself was described as a Magic Box. Magic Boxes would need to be secured from devious people. When the candidates arrive at the island, it is their destiny to "open" the lock in order for Jacob and/or MIB to escape.

The random order of the candidates selection to become island keys came from Jacob scouting them as children, then coming to them with his touch (marking them as elements of the island key). Once they arrived on the island, the game was to determine the order of the candidates in order to unlock the island. It would seem neither Jacob or MIB could control the order of the key, because they were frustrated by the lack of results over the centuries of people being brought to the island.

The only logical progression for the key cuts would be the order of when each candidate died. We know the order from the beginning: Locke (which could be considered a clue for this theory), then Sayid (even after reanimation), Jin, Jack, then most likely Sawyer (if the Ajira plane did not have enough fuel to get home) and then Hurley (who would have become immortal when he accepted the island guardianship).

One might realize a flaw in the theory which is that Jacob and MIB "died" (i.e. escaped) before Hurley would have died. But they could have been trapped like Michael as a whisper, a spirit attached to the island, until Hurley died which would release all the lost and trapped souls into the after life.

THOTH

If the island had name, it would have been Thoth.

Thoth was an ancient Egyptian god-like being who was said to have represented knowledge, science, magic and guidance of souls through the passage in the underworld.

He was often depicted as a half-man, half Ibis. He often helped Ra, the Sun God, through his nightly passage through the underworld. The image of a winged god of knowledge is also found in other cultures, including ancient religions of Hindu, Taoism, and Buddhism.

Thoth's roles in Egyptian mythology were both numerous and varied. First, Thoth served as a mediating power, especially between the forces of good and evil, making sure neither had a decisive victory over the other. This aspect was particularly relevant in his arbitration of the conflict between  Set and Horus.  Likewise, Thoth's mediation role was also evident in his netherworldly alter ego A'an, the god of equilibrium, who monitored the posthumous judgment of deceased mortals and recorded the results in a celestial ledger.

Thoth was also understood to serve as the scribe of the gods, and was credited with the invention of writing and alphabets. As a result, he was also acknowledged as the progenitor of all works of science, religion, philosophy and magic. In the Hellenistic period, the Greeks further declared him the inventor of astronomy, astrology, numerology, mathematics, geometry, surveying, medicine, botany,  theology, civilized government, the alphabet, reading, writing, and oratory.  The Greeks further claimed he was the true author of every work of every branch of knowledge, human and divine.

Thoth was also characterized as a creator deity: the self-begotten and self-produced One. In this context, he was understood to be the master of both physical and moral law, both of which corresponded to the proper understanding and application of Ma'at.  As such, he was credited with making the calculations for the establishment of the heavens, stars, Earth, and everything in them, and to direct the motions of the heavenly bodies.

In this particular context of the Egyptian pantheon, Thoth's this-worldly and other-worldly power was almost unlimited, rivaling both Ra and Osiris.  

Thoth was also prominent in the Osiris myth, being of great aid to Isis. After Isis gathered together the pieces of Osiris' dismembered body, he gave her the words to resurrect him so she could be impregnated and bring forth Horus, named for his uncle. When Horus was slain, Thoth gave the formula to resurrect him as well.

Mythological accounts also assign him credit for the creation of the 365 day calendar. According to this tale, the sky goddess  Nut was cursed with barrenness by Shu, who declared that she would be unable to conceive during any of the months of the year. Coming to her aid, Thoth, the crafty god, discovered a loophole—since the lunar calendar year was only 360 days long, the addition of days that were not contained in any given month would circumvent the hex. Thus, Thoth gambled with Khonsu, the moon, for 1/72nd of its light (five days) and won. During these five days, the goddess conceived and gave birth to Osiris, Set, Isis, Nepthys, and (in some versions) Kheru-ur (Horus the Elder, Face of Heaven). For his exploits, Thoth was acknowledged as "Lord of Time."

All of Thoth's powers dovetail nicely into the various aspects of the elements of the island.  

Throughout the series, the conflicts between the forces of good and evil resulted with neither having a decisive victory over the other. The ideas of lists and missions and judgments follow Thoth's monitoring of  the posthumous judgment of deceased mortals on ledgers. The island was filled with themes of science, religion, philosophy and magic. It would appear that the island had certain unbroken "rules," as stated in the Jacob-MIB conflict which may represent Thoth's mastery of both physical and moral law. In his myths, there are great stories about being a guardian in the underworld and healer of infertility. Infertility and guardianship of the island were two prominent themes in the series. Also, Sayid's resurrection from the dead in the Temple waters was surrounded by columns of ancient Egyptian hieroglyphs which were probably the formula for the ceremony and magic.

The island would best be described as Thoth or his domain. It is apparent that there may have been an unseen entity behind the curtain beyond Jacob or MIB.  With all his powers, Thoth seems to fit the bill as being the man behind such a supernatural curtain.