On Friday, South Korea's National Assembly voted overwhelmingly to impeach the country's embattled President, Park Geun-hye.

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This is the latest step in a baffling scandal that's equal parts Rasputin and Watergate, and which sent millions of citizens into the streets of Seoul to demand Park's ouster. The scandal threatens to alter the course of South Korea's government, and might upend the country's relationship with the US, at a time when President-Elect Trump is already talking of doing so.

Here are some answers to basic questions surrounding the situation. 

Why was Park impeached?

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In late October, South Korean media revealed that Park had been giving enormous access and influence to a woman named Choi Soon-sil. Choi is the daughter of "Eternal Life Church" founder and shaman Choi Tae-Min. Prosecutors and Korean politicians allege that Choi had a dangerous level of sway over Park, editing her speeches (including a key 2014 speech laying out her goal of unifying with North Korea), regularly speaking with her staff, controlling what she wore, and being given classified briefings.

Local media compared it to the influence that "mad monk" Grigory Rasputin had over the Tsar just before the Russian Revolution.

Wait, the head of a key US strategic partner was being controlled by a cult leader's daughter?

That's the core of the allegations against Park. Choi has already been indicted for exerting undue influence over Park, and of using her pull to force the massive conglomerates that control South Korea's economy to donate $70 million to two non-profits she runs, the vast majority of which Choi is accused of embezzling.

South Korea is one of the wealthiest countries in the world - how did this happen?

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Park's father was Park Chung-Hee, pictured third from the right above, who ran South Korea from his seizure of power in 1961 to his assassination in 1979. For much of that time, the elder Park was advised by the elder Choi. The power the shaman had over Park was cited by Park's assassin, the head of Korea's top intelligence agency, as one of the reasons he shot and killed the President.

Choi had been a part of Park Geun-hye's life since 1974, when he clamed he could help Park communicate with her mother — who was also recently assassinated — in the afterlife. When the elder Choi died in 1994, the relationship with the Park family was picked up by his daughter, and only grew in significance. 

Did the protests force her ouster?

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Park apologized several times for the incident, while insisting she did nothing wrong. She was already deeply unpopular, and the breaking scandal sent protestors flooding into the streets of Seoul in October. Six weeks of protests culminated with 1.5 million people marching, a populist wave made up mostly of younger Koreans anxious to put the Park family in the past.

Given the size of the protests and Park's approval rating plummeting to single digits, the National Assembly felt it had no choice but to impeach.

What happens next?

South Korea has entered a leadership vacuum. Park had offered to resign, likely to avoid impeachment, and it was rejected. The country's Prime Minister will temporarily assume Park's powers, and the impeachment now goes to a Constitutional Court that has 180 days to make a final ruling.

Meanwhile, South Korean military officials are preparing for the North to exploit the chaos somehow.

What does this mean for the US?

Assuming Park is removed, a new election will be held 60 days later.

It's thought that her conservative party will be ousted and replaced by a more progressive one favoring cooperation with North Korea. This will likely be at odds with the approach experts believe the Trump administration will take. Trump himself had campaigned on forcing the South to pay for more of its own defense, and suggested that they should develop their own nuclear weapons.

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Yet just days after his election, Trump and Park spoke, with Trump pledging to help repel North Korean aggression.

If Seoul's new government is open to cooperation with North Korea, that could cause Trump to revert back to his original posture, and could lead to the US pulling its 28,000 troops out all together. This would leave South Korea deeply vulnerable to an invasion that would destabilize the world's economy and put Seoul in danger of nuclear attack.

What will happen next is anyone's guess.