Schmidt had been a rising star in the field of theoretical physics in his native Germany, and had actually been a protégé of Albert Einstein at one point in his career. After he began to espouse radical theories on the nature of gravity and the possibility of dimensional travel, his reputation took something of a downturn, and he decided to pursue his research alone.
Believing that in certain places across the globe the barrier between our dimension and others was thinner than others, Schmidt looked into inexplicable disappearances worldwide (reasoning that these disappearances were the result of cosmic gateways), and found that one of the largest concentrations of these was in the town of Arkham, Massachusetts. Packing his bags, he made his way to the United States in order to study this phenomenon in the field.
Upon reaching Arkham, Schmidt was befriended by an elderly lecturer in astronomy from Miskatonic University named Norman Withers, who agreed to help him in exchange for Schmidt’s assistance with his own problem: the fact that six stars had simply vanished from the sky overnight. The two scientists visited some of the sites of the disappearances, and obtained data from the first two which appeared to support Schmidt’s theory. Unfortunately, at the third site, something emerged from the portal which they had been investigating and dragged him off to another plane of existence.
Luckily for Schmidt, his friend Withers chose not to abandon him, and was able to seek out information on how to open a doorway from this world and, after arming himself appropriately, the elderly astronomer set out on a rescue mission.
Travelling through the portal to Tindalos, the home of the extra-dimensional Hounds which had whisked Schmidt away, Withers was able to locate his friend and the pair successfully evaded the Hounds before closing the portal through which they emerged.
Unfortunately for Withers, Claus was unable to assist with the conundrum of the missing stars, but he did vow to continue his research into the dimensional portals, albeit in safer ways than before.