A child is missing in East Berlin, and the RPA's assistance has been requested in the investigation. New agent, Otto Keck has been assigned to the team, and has accompanied Friend and Ziller to the home of the distraught parents. Frau Keller is beside herself with grief, her child Dieter has been missing for three days. The team questions her, gently, to discover that he was a good boy, and very quiet, who rarely got into trouble. He's friends with a girl who's family shares the flat with them, and a few other boys at school. She provides a picture, he's a small boy with blonde hair and blue eyes.
The team slits up to investigate leads, and calls Ko and Patton in for assistance. Friend and Ziller go to the child's school while Keck, Ko and Patton question the father at the factory. From the father, they discover Dieter had recently been in a fight with another young boy at school. Dieter's nose had been bloodied, and he had begged his father not to tell his mother. Dieter didn't want his mother worrying.
Meanwhile, Friend and Ziller interview the principle of the school, as well as Dieter's teacher to discover that many children have actually stopped attending school recently. It isn't uncommon for some children to drop out, they're told, some children go to work to help support their families, particularly the older ones. The teacher is concerned however at the increased numbers, and the age of the children, some very young. Friend and Ziller obtain the records of the children who have stopped attending school, and discover a disturbing trend: many had seen the school nurse, Josephine Metzinger, shortly before they stopped coming to school. Friend and Ziller discretely request that the principle make Frau Metzinger available for questioning, after alerting the other team members of what they've found.
Ko, Patton and Keck leave to meet the rest of the team at the school, but get re-directed to a domestic disturbance by HQ. A disturbance is occuring at the home of one of the missing children. The team arrives to find the Volkspolezei trying to keep the peace, while the father of the second missing child screams at an elderly, nearly naked man. The father screams "How dare you!" while the old man can only sob and mutter the word "Father". The mother sobs quietly in a corner of the apartment.
The team splits up to contain the situation, and learn anything they can. From the mother, they discover that her son has a winestain birthmark on his back. The old man, of course, has an identicle birthmark. He tells them that the last thing he remembers was having an asthma attack at school, and seeing the nurse. Then he woke up outside, cold and weak, but he found the strength to get home.
The principle of Deiter's school tells Friend and Ziller that it's the stranges thing: she told Frau Metzinger that the nice gentlemen from the RPA wanted to talk to her, but now the nurse can't be found anywhere. The agents get the nurse's address and race to the scene, notifying their partners over the radio as they go. Ko, Patton and Keck agree to meet them there.
Frau Metzinger's address is on a block that appears completely deserted. Three agents enter the building from the front, while two obtain access from an alley in the back. In the alley, they discover what looks like a homeless encampment, but all of the men are elderly and most are dead. One of the corpses is so old as to be nearly mummified. He wears a nice suit under a soviet issue long coat, and he still has his identification on him: Grigori Sudakov. A broken syringe juts from his neck.
More determined than ever, the agents break into the house. Patton kicks one door in, while Ko shoots the lock from the other. Within, they find little but dust, but tracks in the dust lead them to a hidden stair. The hidden stair leads them to a laboratory (or as Brendan pointed out, a la-BOR-a-tory, not a labra-tory). Frau Metzinger furiously taps out a message on a telegraph, surrounded by lab equipment and gurneys. One gurney holds a young man, in his mid thirties, connected to feeding tubes and IVs.
The team orders Metzinger to her knees, and Ziller attempts to interrogate. Feigning deafness, Metzinger lures Ziller close enough to attempt to stab him with a syringe filled with a bright blue fluid. The needle sinks in, but Keck is too quick, shooting Metzinger in the arm and preventing her from pushing down the plunger. Patton slams the old woman into the wall, pressing the syringe against her throat.
Meanwhile, Friend disconnects the young man from the equipment. He is emaciated, but alive, with blonde hair and blue eyes; Dieter aged into a man's body. Ko rushes to the telegraph to see a notbook nearby, filled with chemical formulae. One page, the last, has the word SUCCESS written broadly upon it.
Metzinger taunts Ziller, seeming to know him, though he doesn't know her. She tells him that he should pick a side, and when the Furher returns he will want to be on the right side. She then slams the syringe in Patton's hand into her neck, injecting the blue liquid into herself. She drops to the ground and begins to rapidly age and wither, laughing until she begins to scream.
The ticker tape next to Ko begins to move, a message is being received. "I know who you are. Stop. You will not stop me. Stop. The furher will return. Stop. Love and kisses, Uncle Joe."