An Israeli prison guard stands outside Ayalon Prison near Tel Aviv. (REUTERS/Nir Elias)

You might have heard something about the "Prisoner X" story, a complicated scandal, stretching from Israel to Australia, that involves espionage, a mysterious death and press censorship. Here, to help you follow the story and grasp why it matters, is a basic recap and primer.

First, a disclaimer: Much of the world's understanding of this story comes from a single source: a just-out report by the Australian Broadcasting Corp., which has itself become part of the story. I've tried to indicate where the ABC report is the only source.

A simple timeline of what happened

Sometime around 2000, according to ABC, an Australian man named Ben Zygier emigrated to Israel and changed his name to Ben Alon. ABC also says that Zygier/Alon worked for Israel's spy service, Mossad. (Update: The New York Times is now also reporting that Zygier, Alon and "Prisoner X" were all the same person.)

In 2010, Israeli officials arrested Zygier/Alon and placed him in solitary confinement in Ayalon Prison. The ABC report says that he was housed in a special, single-cell "prison-within-a-prison" that was built to accommodate Yigal Amir, the man who assassinated Israeli Prime Minister Yitzhak Rabin in 1995. (Update: The Israeli justice ministry now says that the prisoner – whom they're still not naming – had access to lawyers and was visited by family.) That December, Zygier/Alon hanged himself in his cell.

An Israeli news outlet, Ynet News, reported the man's death at the time, but was not able to identify him. The man thus became known as "Prisoner X." The Israeli government issued a gag order forcing Ynet to remove the story. The gag also prohibited Israeli media from covering the death, the conditions in the prison or even the gag order itself.

On Tuesday, ABC released its report, which identifies Prisoner X as Ben Zygier/Alon and says he was a Mossad agent. Australia's foreign minister ordered a formal investigation into the incident the next day. Also Wednesday, Israel lifted its ban on the ABC report.

Why it matters: (1) Debate over Israeli censorship

Debate has exploded within Israel over both the state's handling of Prisoner X and its strict censorship. On Tuesday, members of the Israeli parliament, known as the Knesset, peppered Justice Minister Yaakov Neeman with questions, some of them clearly reflecting exasperation. “I cannot answer these questions because the matter does not fall under the authority of the justice minister,” Neeman responded. “But there is no doubt that if true, the matter must be looked into.”

Why it matters: (2) Possible damage to Israel-Australia ties

The Prisoner X controversy could be considered a microcosmic example of the Netanyahu government's emphasis on security over diplomacy. The story, which has apparently taken the Australian government itself by surprise, risks damaging Israel's relationship with Australia. That's not exactly an existential threat to Israel except that the country's international support, particularly among Western nations, has been gradually eroding. Australia abstained from a November 2012 United Nations vote, on upgrading Palestine's member status, that Israel opposed.

The New York Times's Robert Mackey writes, "Relations between Israel and several other nations became strained in early 2010 when it emerged that 'Mossad had used the identities of dual nationals living in Israel, including four Australians,' on forged passports used by suspects in the assassination of a Hamas official in Dubai."

In early 2010, the Australian intelligence service began investigating "at least three dual Australian-Israeli citizens whom it suspects of using Australian cover to spy for Israel," according to the Australian  newspaper the Age.

Why it matters: (3) Mystery about Prisoner X's possible crime

It's not known why Prisoner X, who according to ABC was a member of Israel's own spy service, ended up in an Israeli prison. The Israeli government's decision to place him in solitary confinement and the gag order on the media regarding his case certainly suggests he was suspected of something very serious. But, as a number of Israeli politicians have pointed out, we don't know what he was locked up for because the case against him is secret.

What happens next?

Pressure is building in Israel for the government to explain why it detained Prisoner X and kept his arrest, imprisonment and death such a closely guarded secret. This is partly about determining the specifics of his case but also about delineating the acceptable limits of state censorship.

Australia is likely to continue to push for more information and perhaps a public accounting of what happened.

It will be interesting to see how the Netanyahu government, which may be driven closer to the political center after the recent parliamentary elections, responds to the internal and external pressure. That will say something about how it balances security, media freedom and diplomacy.

Update, 4:53 p.m. EST: Israel's justice ministry has formally acknowledged, although has not named, "Prisoner X."

Update, Thursday 10:55 a.m. EST: The Australian foreign ministry has since, according to the New York Times, "acknowledged that 'some officers of the department were made aware' of his imprisonment beforehand 'by another Australian agency.'"