TEHRAN — (CNN) Several Americans have been released from Iran, but their journey is far from over.

From the future of U.S.-Iranian relations to the fate of another missing American, the release could mark just the beginning of more political maneuvering to come.

Here’s the latest on the prisoner swap and what’s next:

Which Americans were freed in the swap?

Washington Post journalist Jason Rezaian, Marine veteran Amir Hekmati, Christian pastor Saeed Abedini and Nosratollah Khosravi-Roodsari were released as part of a prisoner swap.

Rezaian was detained by Iran in 2014 and eventually charged with espionage and other crimes, according to the Washington Post. He was the newspaper’s Tehran bureau chief.

Hekmati was detained in 2011, weeks after arriving in Iran to visit his grandmother, according to his family’s website. The former Marine infantryman and Arabic and Persian linguist was accused of espionage and other charges in 2012.

Abedini, an Iran native and convert to Christianity, was arrested in 2012 and convicted the next year on charges of attempting to undermine the Iranian government. He had been sentenced to eight years in prison.

Not much is known about Khosravi-Roodsari.

Who else was released?

Matthew Trevithick, a student who was recently detained, was also released — but not as part of the prisoner swap. He has left Iran, but officials provided no additional details about his case.

U.S. officials indicated to Iran’s foreign minister “that it’d be important for them to try to resolve some of the other cases of Americans detained in the context of this” deal, a senior administration official told CNN.

Where are they?

Rezaian, Hekmati and Abedini arrived in Germany on Sunday and will be reunited with their families soon, U.S. Secretary of State John Kerry said on Twitter.

The three arrived on a flight at Ramstein Air Base and were scheduled to undergo medical checkups at Landstuhl Regional Medical Center, a U.S. military hospital.

Khosravi-Roodsari decided not to leave Iran senior White House officials said. “It’s his free determination” whether he wants to stay in Iran, one official said. “We don’t make that judgment.”

What happens next?

It’s unclear how long the medical evaluations will take, but the former prisoners are expected to meet with friends and family as early as Monday.

The American Center for Law and Justice, a Washington-based group dedicated to protecting religious and constitutional freedoms, reported that Abedini was tortured during his imprisonment and was beaten by fellow prisoners in June. He suffered injuries to his face during that incident, the center reported.

Hekmati suffered from health problems, including weight loss and breathing difficulties, according to his family.

Jared Huffman, who represents Rezaian and has been involved in his case, said Rezaian, Hekmati and Abedini won’t be on U.S. soil for a few days.

Who did Iran get in return?

In exchange for the American prisoners’ freedom, the United States pardoned or commuted the sentences of an Iranian and six dual citizens of the United States and Iran in what Obama called a “one-time gesture.”

The men allegedly had been involved in exporting products and services to Iran in violation of trade sanctions against the country. They were accused of exporting goods ranging from electronic components and satellite services to marine navigation and military equipment to Iran.

Khosrow Afghahi, Tooraj Faridi, Bahram Mechanic and Nima Golestaneh were pardoned. Nader Modanlo, Arash Ghahreman and Ali Saboonchi had their sentences commuted, the U.S. Justice Department said.

The United States also agreed to drop charges against 14 other Iranians whose extradition to the United States seemed unlikely, a U.S. official said.

Did the nuclear deal play a role?

The announcement of the prisoners’ release came as the United Nations’ nuclear watchdog, the International Atomic Energy Agency, announced Iran is in compliance with a July deal to restrict its nuclear program.

As a result, at least some international economic sanctions against Iran were lifted.

The prisoner swap came after more than a year of secret negotiations, the officials said. The nuclear agreement “accelerated” the exchange, Kerry said.

Is Iran holding any other Americans?

During negotiations, another American’s name was apparently on the table: Robert Levinson.

Iran has denied holding Levinson, a former FBI agent and CIA contractor who went missing there in 2007.

Now the agreement between the United States and Iran calls for Iranian officials to “continue cooperating with the United States to determine the whereabouts of Robert Levinson,” a U.S. official said.

Kerry said Sunday that Iran had agreed to deepen coordination in the search.

“We are happy for the other families,” Levinson’s family said in a statement. “But once again, Bob Levinson has been left behind. We are devastated.”

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