When an Italian appellate court overturned the murder conviction of Amanda Knox and her Italian ex-boyfriend, Raffaele Sollecito, in October 2011, the American foreign exchange student probably thought her legal troubles were behind her.

Nope. On Tuesday, Italy's top criminal court, the Court of Cassation, ordered a retrial for Knox and Sollecito, who are accused of murdering Knox's British roommate, Meredith Kercher, in a brutal sex game gone wrong.

The bad news for Knox is that the Court of Cassation's decision cannot be appealed: There will be a new trial, in Florence, late this year or in 2014. The good news is that the court didn't order her arrest, and even if it had, Knox is in Seattle, far from the arm of Italian law. Sollecito probably won't be re-arrested before the trial, either, his lawyer says. But if the former lovers are convicted, Knox has an advantage over her ex-boyfriend: Italy would have to seek Knox's extradition, and the U.S. would have to approve the request.

Knox is "ready for a new trial, she's gone through this before," says her lawyer, Carlo Dalla Vedova. "She's ready to fight." At the same time, Dalla Vedova says he doesn't think Knox will return to Italy for the retrial. "The psychological stress of the case has been heavy. I don't think that she'll come."

That's a no-brainer, says CBS News legal analyst Jack Ford. "If I'm her lawyer, I'm saying there is no way in the world I'm going to let you go back to Italy and be tried." That means she would be tried in absentia. If she's found guilty, that will raise an "entirely new set of legal questions," the biggest being "whether or not she gets extradited."

But that's not the only looming question. The Court of Cassation rules on process, not the merits of the case — in other words, was the original appellate trial flawed? But the court did not explain what exactly prompted the judges to order a retrial. The court will explain its ruling within 90 days, says Dalla Vedova, and then we'll learn "which points will have to be re-examined." The retrial could hinge on "the DNA, witnesses, or a footprint" that needed clarification, for example.

Knox "thought the nightmare was over," says her lawyer. So did we.