Egypt hangs in the balance. Monday's civilian deaths have inflamed tensions so greatly that the phrase "civil war" is starting to be heard. In that context Adly Mansour, the interim president, did the right thing on Monday by setting out a timetable for constitutional change and new elections. Speed is essential if Egypt's discord is to be channelled back into the political sphere before the situation tumbles out of control.
Egypt's 82.5 million people have lived with almost constant crisis since the fall of Hosni Mubarak in 2011. But with the Muslim Brotherhood now calling for an "uprising" to back Mohammed Morsi, the deposed president, Egypt's shaky politics are suddenly at risk of collapse.
The army claims Brotherhood hardliners began Monday's trouble, but the total of 51 mostly-civilian dead, including women and children, reveals severe military overreaction, at best.
Where will this stop? On Monday a Brotherhood spokesman, saying that protests would continue, cited Syria, a chilling warning of intent to reclaim power at any cost. Egyptians must find a better way to write a new social contract. And that way can be found only in electoral politics.
Lost in the tumult are the real causes of Egypt's problems: a stagnant economy, inadequate infrastructure, rejection by foreign investors and tourists alike, and pervasive corruption. Economic problems can be dealt with only by a stable, competent government. Mr Mansour should form a cabinet promptly, and let it oversee his timetable: 10 legalists assembled to draft amendments to the constitution, an appointed, broadly-based group of 50 to approve these, leading to a referendum just four months from now, parliamentary elections soon after - probably early in 2014 - and finally a presidential vote.
It's all barely possible. But the Salafist party, Al Nour, is now boycotting the government and the process. It has already blocked Mr Mansour's two proposed prime ministers as too liberal.
Re-writing the constitution unilaterally started Mr Morsi's downfall. Mr Mansour's constitutional decree gives the Salafists some of what they had in Mr Morsi's constitution, but Mr Mansour may now have to proceed without them; after all their posturing is not motivated by eagerness to compromise. Still, if Mr Mansour's cabinet and constitutional panel adopt a conciliatory approach, popular support may follow.