The New York Times, Washington Post, and Los Angeles Times all lead with yesterday's surprise Supreme Court decision to take up a case it had previously declined, on whether Guantanamo detainees can challenge their detentions in U.S. courts. The papers agree that it's the first such reversal by the court in decades.

The Wall Street Journal tops its world-wide newsbox with, and everybody else fronts, the other attention-grabbing news of the day: Authorities in London defused two apparent car bombs that targeted the city's busy theater district and that they say could have resulted in large numbers of deaths had the attacks not been averted.

The Supreme Court decision involves a case it refused to hear in April. Justices offered no explanation for the reversal, and the papers say that five votes were necessary to make it happen. The WP, which does the best job of laying out previous Gitmo rulings, notes that John Paul Stevens and Anthony Kennedy said at the time of the April refusal "that they would continue to monitor the legal proceedings involving the detainees … so perhaps the two justices concluded that they have seen enough."

Georgetown law professor Neal K. Katyal, who previously argued a Gitmo case before the Supreme Court, serves as the go-to guy for the NYT and WP, and it's no wonder since he brings the goods: the concise, clear explanation that reporters' crave. He gives slightly varying versions of the same quote, explaining that the case will boil down to this simply stated, yet deeply significant question: "Does the Constitution protect the detainees?"

The issue involves habeas corpus—the centuries-old legal procedure for prisoners to challenge their detentions. The Bush administration's argument that it does not apply to foreigners being held as enemy combatants outside the United States has been one of the reasons why many accuse it of undermining the rule of law.

The London car bombs were discovered by chance. In one case, an ambulance crew noticed smoke inside a Mercedes near the Tiger Tiger nightclub and told police, who later defused it.

As for the other car bomb, parking enforcement officers unwittingly had it removed from the same area. The car, also a Mercedes, was ticketed, then eventually towed away to what the WP says was an underground garage. The paper says, however, that workers didn't notify authorities that the car smelled of gasoline until "many hours later."

The bombs were made with gasoline, nails, and gas cylinders, bearing some similarities to a previous plot to blow up buildings in London. That earlier plot, the so-called "Gas Limos Project," envisioned loading limousines with bombs. The alleged al-Qaida operative accused of planning those attacks is now in prison.

The papers offer a variety of reasons for the attempted attacks, including possibly the most obvious: They were meant as a warning to newly installed Prime Minister Gordon Brown. The stories also note the July 7 anniversary of the 2005 subway and bus bombings in London, while the Post tools around on the Web and reports that "postings on Internet sites" suggest the bombs may have been a response to the queen's decision to make Salman Rushdie a knight.

And since this is London, the papers revisit the stiff-upper-lip angle, serving up examples of weary Brits going about their day's business despite the news.