In November of 1095, a sixty-year-old French pope stood in a field outside the cathedral of Clermont and gave the most consequential speech of the Middle Ages. Eight months earlier, ambassadors from the Byzantine emperor had asked him for a few thousand professional knights to help fight the Seljuk Turks. Standard contract work. Urban II sat with the request through the summer, then walked outside on November 27th and offered something nobody had ever heard before. Full remission of sins for everyone who took the cross. The crowd shouted back, "Deus vult." God wills it.

They asked for soldiers. He gave them a holy war.

This week we hit Control Z on the speech that launched the Crusades, and follow what happens when one man writes the smaller answer.

In September of 2000, three guys from a tiny DVD-rental startup called Netflix flew to Dallas on a chartered jet they couldn't afford to make a pitch to the most powerful video rental chain on Earth. Reed Hastings asked Blockbuster CEO John Antioco for fifty million dollars. Antioco's mouth twitched at the corner. His general counsel told the room the dot-com hysteria was overblown. The Netflix guys flew home crestfallen. Today Netflix is worth four hundred billion dollars, and the only Blockbuster left in America is a tourist attraction in Bend, Oregon.

He almost said yes.

This week we hit Control Z on the deal that would have killed Netflix in the crib, and follow what happens when one man writes the check.

In April of 1979, the Chicago Bulls had a coin flip against the Los Angeles Lakers for the first pick in the NBA Draft. The Bulls' marketing department had run a fan vote on what to call. Heads won. Bulls GM Rod Thorn, who'd called tails his entire life, looked down at the marketing handout and said heads. The coin came up tails. The Lakers got Magic Johnson. The NBA you know was built on what came next.

He almost called tails.

This week we hit Control Z on the coin flip that built the modern NBA, and follow what happens when one man trusts his gut. Showtime, the Bulls dynasty, Phil Jackson, all of it changes.

In December of 1936, King Edward VIII signed a piece of paper that changed a thousand years of British monarchy. He gave up the throne to marry Wallis Simpson, an American divorcée his government refused to accept as queen. His brother Bertie became George VI. Bertie's daughter became Queen Elizabeth II. The House of Windsor you know exists because of what Edward signed that day.

He almost didn't sign.

This week we hit Control Z on one of the closest-run constitutional crises in British history, and follow what happens when a king who wants something more than the crown decides to keep both. The ripples reach further than you'd think.

In December 1989, NBC had a pilot nobody wanted. "The Seinfeld Chronicles" had tested as one of the worst pilots in network history, the president of entertainment called it "too New York, too Jewish," and Fox had already passed. The show was dead. Then a specials executive named Rick Ludwin canceled a Bob Hope special on his own budget and used the money to order four more episodes, the smallest sitcom order in American television history.

But what if he doesn't? What if Ludwin lets the pilot die the way everyone at NBC expected? What happens to Larry David? What happens to the next 35 years of American comedy? And does the last great shared audience in American television history ever exist at all?

On December 10, 1996, Apple was months from bankruptcy and out of options. Two men flew to Cupertino to pitch their software as the company's last hope, Jean-Louis Gassée and Steve Jobs. Apple picked Jobs and used the software he brought with him to build the iMac, the iPod, the iTunes Store, and the iPhone.

But what if Gassée hadn't phoned it in? What if Apple picked the other guy and Steve Jobs never walked back through that door? What happens to Apple? What happens to the smartphone? And does the 21st century we're living in show up at all?

On August 8, 1974, Richard Nixon announced his resignation rather than face near-certain impeachment and removal. Barry Goldwater told him he had 15 votes. He needed 34. So he quit. But what if he didn't? What if Nixon told Goldwater to go to hell and forced the United States Senate to remove him? The trial would have been the biggest television event in American history, playing out during a midterm election, with a president who still controlled the military, the intelligence agencies, and the nuclear codes. What happens to the country? What happens to the Republican Party? And does the politics of grievance that defines America right now show up 40 years earlier?