From Jacob to the polar bears, we decode the most intriguing elements of the ''Lost'' universe

By Adam B. Vary
May 07, 2010 at 04:00 AM EDT

Adam and Eve
The names Locke gave two skeletons that Jack and Kate found in caves near the crash site. Lying next to each other, the pair had a bag containing two rocks — one black, one white.

Bad Twin
A novel ”written” by Flight 815 passenger Gary Troup (a.k.a. the dude sucked into the jet engine) about a PI searching for a twin brother named Zander — wait for it — Widmore.

Cassidy and Clementine
Cassidy (Kim Dickens) persuaded Sawyer to teach her the long con, but became his mark instead. As a capper, he got her pregnant with daughter Clementine. Cassidy also helped a fugitive Kate confront her mom.

The Dharma Initiative
Funded by the enigmatic Alvar Hanso, Dharma built multiple stations (the Swan, the Orchid) throughout the Island in the 1970s in an effort to study its unique properties, like the ”exotic matter” that allowed Sawyer, Jin, Juliet, et al. to join Dharma — in 1974.

Actress Nikki Fernandez (Kiele Sanchez, above with Billy Dee Williams) guest-starred on the season finale of this ”hit” TV series after sleeping with producer Howard L. Zukerman. She then killed him, with the help of boyfriend Paulo (Rodrigo Santoro), for his $8 million in diamonds. The couple took ill-fated Flight 815, got poisoned by spider venom, and were buried alive.

Faraday, Daniel
Brain-melt alert: Faraday (Jeremy Davies) studied the physics of time travel at Oxford at the urging of his mom, Eloise (Fionnula Flanagan), even though she had already killed her time-traveling son in 1977, before he was even born.

Gale, Henry
He was a hot-air balloonist from Minnesota who crashed on the Island and died soon after. Ben used his name and story to infiltrate the survivors’ camp, until Sayid dug up the real Henry Gale’s wallet and found his driver’s license.

Hydra Island
This smaller isle (named after the Dharma station it houses) sits near the main island. It’s where Ben held Jack, Sawyer, and Kate captive; Ajira Flight 316 crashed; and Widmore based his reclaim-the-Island operation.

Asthmatic Shannon Rutherford (Maggie Grace) lost hers after the crash. Years later, Island returnee Hurley found it outside the Adam and Eve caves.

The Others’ true leader, Jacob (Mark Pellegrino) lived in the base of a statue of the Egyptian goddess Taweret. His hobbies included weaving, fishing, and luring people to the Island to prove humanity’s worth. He’s ageless, but — thanks to the knife Ben stuck in his chest — not immortal.

The freighter that Charles Widmore hired to transport his team — including Faraday, psychic Miles Straume (Ken Leung), pilot Frank Lapidus (Jeff Fahey), and mercenary Martin Keamy (Kevin Durand) — to the Island to capture Ben.

This coastline tower was rigged with mirrors that allowed Jacob to peer into the lives of his candidates, each of whom has a numeric designation based on an apparent 360-degree scale. (See: The Numbers.) When Jack saw his childhood home in the mirrors, however, he smashed ’em to smithereens.

Mittelos Biosciences
A fake company the Others used to recruit people (including Juliet) to the Island.

The Numbers
Hurley won millions by playing them in the lottery, but felt cursed by bad luck. Desmond failed to type them into the Swan station terminal, and Flight 815 crashed. And Jacob assigned the digits to six of his potentials: 4 for Locke, 8 for Reyes, 15 for Ford, 16 for Jarrah, 23 for Shephard, and 42 for Kwon.

The Others
What Rousseau and the Flight 815 survivors called the ”indigenous” residents of the Island. Dharma called them the Hostiles, which may be more accurate: They safeguard the Island’s secrets with brutal efficiency.

Polar Bears
A bear vigorously greeted the castaways on their first day. Dharma kept several in cages on Hydra Island, and somehow at least one of the animals was transported to the Tunisian desert.

Dharma stamped the word on the Swan station hatch in a likely effort to keep people inside it. But it could also refer to the strange sickness that claims those who meet the Smoke Monster…

Michael built the craft (twice!), then tried to sail away on it, along with Sawyer, Jin, and Walt. The Others stopped them, abducted Walt, and torched the raft.

Smoke Monster (a.k.a. Smokey)
Presaged by a ticka-ticka sound, it usually appears as a cloud of black smoke. It can scan the memories of the living and take the forms of the dead — including Christian Shephard and John Locke. A contemporary (and mortal foe) of Jacob’s, it is desperate to escape the Island.

Surrounded by a giant stone wall, decorated with hieroglyphics, and riddled with musty catacombs, it served as a sacred place for the Others. It held a bubbling spring of water that could heal the dying — at least until Ben killed Jacob, at which point it looked more like a dirty hot tub and seemed to make Sayid evil. Sayid killed the Temple’s steward, Dogen (Hiroyuki Sanada), whose death allowed the Smoke Monster to storm the gates and wipe out everyone inside.

A stone monolith in the Australian outback, it’s one of several spots in the world with mystical healing powers. Bernard (Sam Anderson) brought his wife, Rose (L. Scott Caldwell), there hoping to cure her terminal cancer.

A seemingly invincible Labrador retriever, Vincent was originally owned by Michael’s son, Walt (Malcolm David Kelley). Shannon cared for him for a brief time. Finally, Bernard and Rose took him into their jungle retirement hut.

Watership Down
Sawyer’s favorite book, by Richard Adams, is about a society of rabbits who seek a new home and fall into a false utopia. It’s one of dozens of Lost literary references, including Lewis Carroll’s Alice in Wonderland, Fyodor Dostoyevsky’s Notes From the Underground, and, you know, the Bible.

These scans revealed the life-threatening tumor on the L4 vertebra of Ben’s spine.

The younger brother of Flight 815 survivor Mr. Eko (Adewale Akinnuoye-Agbaje), Yemi (Adetokumboh McCormack) was a Nigerian priest who died in a small drug-smuggling plane that crashed on the Island.

Geophysicist Zoë (Sheila Kelley) was Charles Widmore’s second-in-command for his final Island campaign. She’s more scientist than fighter, though, if her shaky gun-handling is any indication.