A soldier chases a young boy in an attempt to save him during a massive battle.

Unfortunately, a hand mine reaches out from the mud and pulls the soldier under. As hand mines surround the boy, a familiar sonic screwdriver lands at his feet. "Your chances of survival are about one in a thousand, so here’s what you do. You forget the thousand, and you concentrate on the one" the Doctor calls out.

When he asks for the boy's name, the Doctor is horrified to hear... "My name is Davros."

Meanwhile, Colony Sarff visits The Maldovarium, The Shadow Proclamation, and Karn in search of the Doctor. "Davros knowssss. Davros rememberssss" he tells the Sisterhood of Karn. The Doctor witnesses this exchange, but remains hidden in the shadows.

Colony Sarff returns to his master, Lord Davros, who advises him in order to find the Doctor seek his friends. 

Back on Earth, Clara is teaching her class when she notices a plane frozen in mid-flight.  #PlanesHaveStopped

U.N.I.T. contacts Clara and together they learn it's none other than Missy who is responsible. "Okay, cutting to the chase. Not dead, back, big surprise, never mind" Missy announces demanding to meet with Clara. The Mistress informs the Doctor's companion that he's missing and has delivered his last will and testament to his closest friend. Nope not Clara, but Missy. What?!?

"He's not your friend. You keep trying to kill him" Clara says. "He keeps trying to kill me" Missy replies.

When Clara attempts to make sense of all this and questions whether Missy has turned "good." The villain proves she's as twisted as ever by vaporizing a couple of U.N.I.T. agents stationed nearby. The two come to an agreement and Clara figures out the Doctor is hiding out in 1138 A.D.

Missy reaches over and touching Clara's arm transports the two of them to the Doctor's location.

The Doctor enters the arena not only riding a tank, but shredding power-chords like a rock God!

He spots both Clara and Missy and introduces them to a very confused medieval crowd.

Suddenly, Colony Sarff appears and informs the Doctor that Davros is dying and wishes to speak to him one last time. The snake nest in a dress agrees to spare everyone present if the Doctor takes this meeting. He then throws the Doctor's old screwdriver to the ground.

"That's yours?" Clara asks. He shamefully confesses he no longer carries a sonic screwdriver. The Doctor remembers abandoning young Davros on that battlefield and agrees to leave with Sarff. Clara and Missy demand to go along as well.

"How scared must you be to seal every one of your own kind inside a tank? Davros made the Daleks, but who made Davros?" the Doctor wonders aloud as they arrive at their destination.

Sarff takes the Doctor to Lord Davros, but Clara and Missy are forced to stay behind.

While the Doctor and his nemesis chat, Missy realizes they are not on a space station but a planet. That's right, they're on Skaro! The planet of the Daleks.

Davros scolds the Doctor for his actions and torments him with voices from his past. "Compassion Doctor. It has always been your greatest indulgence" Davros says as Daleks surround his friends.

Though he gave these monsters life, Davros can not control them.

The Daleks swiftly exterminate both Missy and Clara as the Doctor looks on in terror. They then set their sights on the TARDIS and destroy it as well.

Young Davros turns to find the Doctor standing behind him. He points a gun at the boy and yells Exterminate!