More and more, the answers seem connected to time travel - with a possible Philadelphia connection - or to some gigundo hoax/brainwashing fraud.
The bear discovery is made as a flashback introduces Charlotte Lewis, a cultural anthopologist who finds what seems to be a Dharma Initiative symbol on a tag next to the bear.
Switch to the island, and she's dangling from parachute cords over a cliff, part of a team of four new characters who choppered over not to rescue anybody but to kill Ben Linus, the bug-eyed creepazoid turned captive punching-bag who once led "The Others."
Ben grabs a gun and shoots Charlotte, who's dazed but undamaged because of her bulletproof vest.
Poor, Ben. Put a bullet through Locke's chest - clean through, Sawyer, see the scars? - and Locke lived, thanks to Walt, he says. You'd think Ben might have learned a lesson and aimed between the eyes.
As Locke's about to kill Ben, the bleeding sniveling rotter tells all about the phoney-baloney "rescuers":
Besides Charlotte, there's physicist Daniel Faraday, ghostbuster-with-a-Dustbuster Miles Straume and pilot Frank Lapidus.
We later learn they were all recruited by the same tall, gaunt guy in a suit we saw last week interrogating Hurley at the sanitarium.
The flashback about Miles suggested ghosts are real in the world of Lost, as Miles tricks a ghost into revealing where stolen moolah was stashed.
Later, on the island, Miles "talks" with supposedly dead Naomi, who parachuted in toward the end of last season.
Makes one think: Maybe Hurley wasn't hallucinating when he saw Charlie's ghost - or when he apparently saw Jack's dead dad in a mysterious cabin.
Pilot Frank's flashback was also mind-bending. When scenes of Oceanic 815 wreckage are on the news, he tells the FAA that couldn't be the real pilot's body - it had no wedding ring.
Besides, early in the first season, we bloody well "saw" the pilot get snatched from the tree-held cockpit by some T. Rex Invisiblosaurus.
Now for some theories:
The polar-bear fossil: Remember the cages that held Kate and Sawyer? They once held bears. Maybe polar bears. After all, we saw at least one bear on the island - it attacked Mr. Eko. We also know the island was once used by Dharma Initiative scientists who did all sorts of experiments. How about this: They did time-travel experiments - and sent a polar bear back through time and space. So far back, it wound up being discovered eons later as a fossil in a desert, still wearing a Dharma tag.
(Well, what do you know? A check online confirms that symbol on the tag is for the very same Dharma station where the cages were!)
This calls to mind - as fans online have long been mentioning - the famous Philadelphia Experiment. In that legendary tale, the Navy used powerful magnetic fields to try to render an entire ship invisible. Instead, it vanished - and showed up at the Philadelphia Navy Yard, some of men aboard supposedly losing their minds, others losing their lives, even getting fused into walls and bulkheads.
Wait, invisibility, time travel ... What if the pilot-munching "monster" was an invisible T. Rex, brought back from the Cretaceous?
Ghosts and time travel seem to be real on Lost.
Unless, of course, those bear bones were planted as part of a plot.
Da plane, boss, da plane. How can wreckage and passengers be simultaneously be waterlogged and beachbound? The para-science explanation is to invoke quantum mechanical multi-universe mumbo jumbo and posit that when the plane split, time and space were split as well - creating two planes. One that sank. One with survivors.
After all, Desmond seems to live in a world of multiple timelines. In one, Charlie's killed by lightning. A little tweaking - by rigging up a golf club - and Charlie dies a drowning hero instead.
If this island reality is also in the past, that might explain how Locke can walk, Rose can be cancer-free and Jack's dad could be alive. The island timeline is simply "before" they got roughed up by fate.
Of course, the arrival of the Let's Get Ben Brigade kind of belies the back-in-the-past idea.
So, sure, this magical magnetically powerful island does some freaky-deeky paranormal Psychic Friendly things - which might be why outsiders are so eager to find it - but the doppelganger-timeline theory might just be a red herring.
The second plane could be a hoax. That's also pretty hard to fathom, though. How and why would any enterprise submerge a plane and put bodies on board?
Could Ben, for example, have a much bigger off-island network than we know about? One capable of creating such a coverup hoax, to saveguard the island's secrets?
More plausible, of course, is that the underwater footage was PhotoShopped, not that the wreckage was.
Which raises the question of why this group of "rescuers" got so intrigued about the crash - and then set out to off Mr. Googly Eyes.
Fans have long wondered if the accident was itself part of a plot. If the fliers were chosen by some conspiracy, that would explain how their lives intersect in more ways than coincidence could.
An early theory online was that the island, with its protective magnetic fields, is a magnetically protected haven where these hand-picked folks could repopulate the planet after a civilization-erasing catastrophe, like the flip-flopping of the Earth's magnetic fields.
Then again, the original air accident seemed to have been triggered by chance - when Desmond left his station at the Hatch, afraid his sailboat might be stolen.
Clearly, there are conspiracies afoot - including the show's creators conspiring to mislead us, and lead us on.
Maybe there are two planes and two realities.
But, as pilot Frank suspected on seeing that pilot's bloating floating body, something sure smells fishy.
Contact staff writer Peter Mucha at 215-854-4342 or firstname.lastname@example.org.