They are the most unlikely of bedfellows.
She is the privileged daughter of a powerful landowning family who had her schooled at Radcliffe and Oxford.
He was born the son of a government clerk and worked his way up through the army ranks on his own steam.
She is a lifelong opponent of military rule who saw her own father overthrown by the army and then executed.
He took power in a military coup and says only the armed forces can keep Pakistan safe from its enemies.
Over the years, Benazir Bhutto and Pervez Musharraf have condemned each other in the strongest terms. She calls him a "military dictator." He has accused her of leading a corrupt "sham democracy" in her two stints as prime minister.
Yet, as improbable as it seems, Ms. Bhutto, 54, and General Musharraf, 63, appear to be drawing closer to a deal that could see them rule Pakistan side by side.
Since the two met secretly in Abu Dhabi last Friday, Pakistan has been alive with speculation about a deal of breathtaking expediency: He lets her return to Pakistan to run once again for prime minister, she agrees to have him stay on as president.
The arrangement would give him the political support he has always lacked and her a chance to come back from exile and take centre stage again. It might just work because, like all good deals, it gives both sides what they need.
"In Pakistan politics, someone once said, enemies become friends overnight if the requirement is there," said Rahul Roy-Chaudhry, who follows South Asian affairs at London's International Institute for Strategic Studies.
Together, supporters of the deal say, the two old foes could make a powerful alliance against the rising forces of Islamic militancy in Pakistan. Washington is thought to be quietly pleased.
Even a few months ago, the notion of a Bhutto-Musharraf pact seemed far-fetched. Though their camps have been in on-and-off touch for years about forging an arrangement of mutual self-interest, the President apparently felt the dangers of inviting his fiercest rival to come home were too great.
All that has changed with the recent fall in his fortunes. He miscalculated badly by trying to oust the unco-operative Chief Justice, Iftikhar Mohammed Chaudhry, a move that set off the worst anti-government protests of the eight-year-old military regime.
An opinion poll released yesterday showed that two-thirds of respondents said Gen. Musharraf should quit. His plan to have the tame, outgoing national assembly vote him to another term in office no longer looks possible.
A second challenge comes from Islamic militants. They have been holding rallies and attacking military installations since government troops stormed Islamabad's Red Mosque to end an Islamist occupation last month and left more than 100 people dead.
Add in the growing displeasure from Washington, which sees al-Qaeda and other militant groups growing stronger in Pakistan's frontier regions despite $10-billion (U.S.) in U.S. military aid, and Gen. Musharraf finds himself in a box.
Turning to Ms. Bhutto and her Pakistan Peoples Party could give him just what he needs: a way out.
"If the PPP, the party with the largest popular base, supported his re-election, he could remain in power for another five years, but with far more legitimacy," the International Crisis Group said in a report this week.
Ms. Bhutto also stands to gain from the proposed deal. If she returns and runs for office again, in an election expected late this year or early next, her party is expected to win the largest number of seats in parliament, giving her a good chance of becoming prime minister for a third time and fulfilling her hopes of working for a more modern, more liberal Pakistan.
Looking at it less charitably, she could continue her family's dominance of the country's politics, gain back lost business interests and carry on the Bhutto dynasty by grooming her son for office.
"She has been in exile for years and this may be her last chance to make a personal return to the country," said former U.S. State Department official Daniel Markey, a Pakistan specialist.
Both Ms. Bhutto and Gen. Musharraf will need further concessions before they strike a deal. Ms. Bhutto needs assurance that the government will drop any remaining graft charges against her and that a way will be found of overcoming a constitutional bar, imposed by Gen. Musharraf, against anyone becoming prime minister three times.
Ms. Bhutto also says that she wants the general to give up his post as army chief if he stays on as president, because "a president in uniform and democracy cannot go together." Reports in the Pakistan press say she might accede to the general keeping his uniform for the coming election if he agreed to resign later as army chief.
Gen. Musharraf, for his part, would probably insist on guarantees from Ms. Bhutto of the military's internal autonomy and of its dominant role in defence and security affairs, concessions Ms. Bhutto has made while in office before.
There are other problems. It is far from clear how, exactly, two such powerful figures would share power.
Even if they managed it, both would pay a price for such a deal. Ms. Bhutto admits her "political credibility" would take a hit if she made peace with a ruler she has condemned so forcefully.
Each could face a revolt from their party members over the prospect of such an unsavoury alliance. But, for both, the enticements of such a strange but coldly logical deal may overwhelm the risks.
