Kirschner is visited by The Witness at an unknown point in time. He is tasked with creating a breed of people immune to the ravages of time. In addition to aging slower, Kirscher's subjects are also incredibly resistant to damage.
By 1961, Kirschner has created Olivia. She is created using Mantis's DNA and eggs. Kirschner is abducted by Ramse and Cassie in Berlin. They encounter Mossad agents, who are looking for Kirschner. They are rescued by James Cole. Kirschner takes the team to his lab, where Olivia is being held in a box-like room. He also possesses the Word of the Witness in his lab. His betrayal is known to the Army of the 12 Monkeys, who infiltrate his lab and take Olivia. Kirschner is killed in the process.
Kirscher's ultimate work is finally realized, with the Army of the 12 Monkeys creating the twelve Messengers based on Olivia's DNA. The time loop is completed when Mantis returns to 1944, ensuring that her DNA would be researched by Kirscher to create Olivia.