In December of 1135, Henry the First of England died in Normandy, and the man best positioned to take his throne had already sworn twice not to. Henry had made every baron in his kingdom kneel and lay a hand on a chest of saints' bones, promising to crown his daughter Matilda after him. One chronicler says Stephen of Blois pushed to reach the relics first.

Stephen took a ship instead.

He was crowned at Westminster three weeks later, and England spent the next 19 winters tearing itself apart. A monk at Peterborough wrote that Christ and his saints slept. Out of that wreckage, Matilda's son built the writs, the traveling judges, and the 12 sworn neighbors that England, the United States, and most of the Commonwealth still run their courts on.

What if he'd kept his word?

This week we hit CTRL+Z on December 22nd, 1135, and follow the ripple to today:a woman crowned at Westminster 4 centuries before Mary the First, a warlord who dies old in his bed instead of excommunicated in the Fens, a child named William Marshal who never gets handed to a king as security for his father's promise, a northern border that stays where Henry the First left it, and an ordinary man with a stolen field who waits two generations for a court that will hear him. England came within one kept promise of its first queen, and the broken one is where the common law came from.

In 1980, the most respected executive in America needed a successor. Reginald Jones ran General Electric, a company of 400,000 employees and the last original member of the Dow, and he chose by calling each finalist into his office and asking the same question: you and I die in a plane crash, so who should run the company?

Jones picked Jack Welch.

Wall Street crowned him Manager of the Century, every boardroom in America copied him, and the doctrine he made respectable, the shareholder above everything else, still runs the economy you live in.

What if Jones had picked the engineer?

This week we hit Control Z on the vote of December 19, 1980, and follow the ripple to 2026: corporate raiders who die as convicts instead of prophets, two planes that land safely on mornings we remember for crashes, a machinist in Erie with a pension, and a middle class that never stopped getting raises. The old American deal came within one boardroom vote of surviving, and the man who killed it built his creed on its ashes.

4th of July Episode!

In 1776, one British general had George Washington cornered. Washington's army was trapped on a strip of high ground in Brooklyn, its back to a river with no boats, beaten and out of room. General William Howe's officers begged him to storm the position and end the revolution that afternoon. He told them to wait, and two nights later a storm and a fog let the entire rebel force slip across the water and escape.

That pause saved the United States before it existed. Howe had already lost more than a thousand men climbing a hill into American guns near Boston, and he refused to spend that many again for a victory he thought he could win slowly. His caution handed the rebellion seven more years, a French alliance, and eventually a country.

What if Howe had given the order to attack?

This week we hit Control Z on the assault Howe refused to launch, and follow the ripple all the way to 2026: a Washington who dies a forgotten farmer, an America that grows old under the Crown, a French king who keeps his head, and a twentieth century with no world wars to fight. The most powerful nation on earth came within one afternoon of never being born, and the man who saved it was trying to win the war for the other side.

In 1991, the men around Mikhail Gorbachev spent two years begging him to send in the army and hold the Soviet Union together. He had already ordered three crackdowns that left unarmed civilians dead, but when it came time to crush the republics for good, he refused. By the end of that year the largest empire on earth had dissolved, and in Russia they have cursed his name ever since.

It almost went the other way. The crackdown his hardliners wanted had been on the table the entire time, and the only real questions were who would give the order and whether the soldiers would obey. Across the same years, the other great communist power made the move Gorbachev wouldn't, sending its tanks into Tiananmen Square, and it's still standing today, richer and stronger than the Soviet Union ever was.

What if Gorbachev had given the order himself?

This week we hit Control Z on the order Gorbachev refused to give, follow the surviving Soviet Union all the way to 2026, and find the lesson underneath: the choice his own country can't forgive is the one that ended the Cold War and set Eastern Europe free.

In 1981, a study Kodak paid for and signed told the company that digital photography would kill film within a decade. Kodak read its own warning and used it to squeeze a few more years out of film instead. The company that invented the digital camera filed for bankruptcy in 2012.

It almost went the other way. Kodak got two clean chances to undo the same mistake, the first in 1981 and a second in 1996. Across the Pacific, a company caught in the identical trap made the move Kodak wouldn't, and it's still here today, inside most of the screens on Earth.

What if Kodak had believed its own people?

This week we hit Control Z twice on the warnings Kodak refused to read, follow both timelines forward, and find the lesson underneath: an early warning is only worth anything if you use it to leave.

In 216 BC, at a place in southern Italy called Cannae, Hannibal destroyed the largest army Rome had ever raised, tens of thousands killed in a single afternoon. With the capital nearly defenseless, he chose not to march on it. That restraint let a broken Rome survive, and the Republic that lived went on to build the Western world.

It almost went the other way. Hannibal's own cavalry commander, Maharbal, urged him to take the horsemen and ride through the night, swearing they'd dine in the enemy capital within five days. Hannibal said he needed time to think. The reply Maharbal threw back has echoed for twenty-two centuries: you know how to win a victory, but you don't know how to use one.

What if he'd listened, and turned the horses north at dawn?

This week we hit Control Z on the victory Hannibal couldn't use, follow the march to the gates of Rome, and the very different world it leaves behind.

In December 2000, the Supreme Court stopped Florida's recount and let George W. Bush's 537-vote lead stand. Those votes, out of nearly six million cast, decided Florida, and Florida decided the presidency.

It almost went the other way. Seven of the nine justices agreed the count was broken. They split on the fix. Five voted to stop. Four voted to send it back, set one standard, and finish. The man in the middle was Anthony Kennedy, who agreed the recount was broken and then voted to end it instead of fixing it.

What if he'd changed his mind on that one question, and said count it instead of stop it?

This week we hit Control Z on the vote that didn't switch, follow the recount to its finish, and the very different country it leaves behind.

In October 1555, a dying Charles the Fifth split the largest empire in Europe between two heirs. Spain, Italy, the Netherlands, and the silver of the New World went to his son Philip. The imperial crown, plus Austria and the lands to the east, went to his brother Ferdinand. The most powerful man in Christendom looked at everything he held and cut it in half.

He almost didn't. Years earlier, Charles had schemed to keep it whole, to put every crown on his son's head and make Philip both King of Spain and Holy Roman Emperor. The plan died in a family fight. The empire stayed divided.

What if it hadn't? What if one devout, distant, Spanish king had inherited the whole thing, and then tried to rule German princes who'd never accept him?

This week we hit Control Z on the division, and follow the unbroken empire as it breaks everything it touches.