You've heard of a blood bath, right?

This week, Lost - shockingly, dramatically, poignantly - introduced us to a sub bath.

Lapidus is dead. Sayid is dead. Sun is dead. Jin is dead. And, after months of debate, let there be no doubt: the Man in Black is not anyone's friend.

We've been aware that not all characters would make it to the series finale, but we never expected so many deaths to take place in one episode.

When asked why "The Candidate" was filled with such sorrow, producer Carlton Cuse told EW.com it was to prove that the "show is willing and capable of killing anyone." Also, to send a message about the man masquerading as Locke:

“There is no ambiguity. He is evil and he has to be stopped."

Because there was little mythology this week (the show is saving that for next week's monumental episode, which focuses entirely on the history of Smokey and Jacob), let's mourn those whose island lives have come to and end...

Lapidus: Always good for a wise crack to lighten the mood, we'll miss this pilot, about whom we must wonder: why was he on the island? We never got a real flashback, his presence never served much of a point. Will we ever learn more about this character? Or was he simply around so we would believe the castaways might leave via the plane because a pilot was among them?

Sayid: In the end, he proved to be good. Following his actions in the war, this was a man that believed he was eternally damned. Even when he fell in love (Nadia, Shannon), he was around when those women died. These tragedies allowed Sayid to wallow in his own form of self-pity, which manifested itself in violent, dark ways.

But he never fully lost his humanity, and when forced to make a split-section decision, he made the ultimate sacrifice for his friends. The question, of course, remains: what the heck happened to him? What "darkness" was Dogen referring to and how did the Temple make him into such a zombie? We assume these answers are to come.

Sun & Jin: Their reunion lasted a week, but their death will be remembered for a lot longer than that. I was afraid for their lives as soon as viewers were made privy to the conversation about daughter Ji Yeon staying with Sun's mother. Dropping that nugget on us didn't bode well for the girl's parents.

One complaint about this death scene: no mention of Ji Yeon? Really?!? As admirable as it was for Jin to remain with his wife, I was distracted by the thought that Sun should be pleading with Jin to leave, for the sake of their daughter.

The tears Lost fans will shed over this couple's passing speaks as much to the show's brilliance as it does to the pair's love. It's impossible not to think back to the first season, where Sun and Jin weren't close, where the former had recently contemplated leaving the latter, and where the latter didn't even speak English.

Fast forward a few years and they became one of the most iconic couples in TV history. It's a testament to Lost that - while throwing jaw-dropping twists, turns and storylines at us - it could also develop such layered, interesting characters. It's their journey that truly carries this show.

Of course, Sun and Jin's demise also makes us think: they were drowned. So was Charlie. The island is submerged in the Sideways World. Is there any significance to these watery deaths?

Among other notes, observations and questions from the episode:

• Fake Locke clearly planted the explosives on the plane and had a plan all along. But he also grabbed the watch off that dead guy, making it seem a bit impromptu. Earlier in the hour, Widmore told his group to speed up its plans for the fence because "he's coming."
• It may mean nothing and it may be nit picky, but there have been multiple instances such as these where things didn't go exactly according to plan (another example: Widmore had yelled at his team previously for picking up Jin earlier than discussed). Might Jacob be pulling some strings, putting little dents into these machinations, all with some grander goal in mind?
• They didn't throw in that shot of Jin, alive, in the Sideways World randomly. I continue to believe this is the universe in which the characters will all end up.
• Bernard!!!
• Locke's Sideways life raises numerous questions: He may have the love of Helen, but he's in the wheelchair, wrecked with the guilt of essentially killing his father, with whom he shared a close, loving relationship. Almost every other character's Sideways world has been free from such burdens. These individuals may be realizing that they're missing something in their lives, but only Locke is faced with such an overriding hardship. Why? What makes him different?
• Push the button. I wish you believed me. Chilling moments, chilling words from an unconscious Locke and sentimental reminders of important instances on the island. Also, triggers to a connection with the Island world? Jack's reiteration of the second line stopped Locke in his tracks.

What did you think of the episode? Can you believe so many characters were killed at once? Is there anything more heartbreaking than Hurley crying? Sound off now about the most memorable developments from "The Candidate."

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.