Dr. Zimmer was born in 2219. At the age of 58, he is a very serious, very straight-forward scientist who has traveled to Rivet City from the Commonwealth (Massachusetts) and is in town on business for "the Institute." Zimmer is looking for an escaped robot, an experiment that, in Zimmer's words, is "unstable, and a danger to himself and others." He is, without exception, always in the company of his bodyguard, Armitage.
After picking up the trail once he got to the Capital Wasteland, Zimmer eventually made his way to Rivet City in the hopes that fellow scientist Dr. Madison Li could assist him in his search for his missing android. On arrival to the Rivet City science lab, he was refused the right to speak with Li by Anna Holt, Li's assistant. Despite being refused assistance, he remains within the lab, refusing to leave and demanding to speak directly with Li. He will refuse to leave until Li "...stops playing with her chemistry set and starts talking real science." It should be noted that Dr. Zimmer shows utter contempt and disgust for Rivet City and its residents.
"Harkness, you say? Yes... Yes, that makes sense. He used to work for a special branch of the Commonwealth Police, after all... And he's right here in Rivet City! Excellent! I must wait... find an opportune moment to confront him... Thank you for your discreet assistance, and continued discretion regarding this matter. And now for your payment. This combat module will directly affect your central nervous system. I think you will find it quite beneficial."