Stuttgart is the capital of the state of Baden-Württemberg in southern Germany.
Loki traveled to Stuttgart to find Heinrich Schafer, a scientist with access to a warehouse containing Iridium, an element Erik Selvig needed to stabilize the inter-dimensional portals created by the Tesseract.
Loki infiltrated a gala where Schafer was a guest speaker, and personally attacked him to create a diversion while Clint Barton raided the secure installation where the Iridium was contained. Loki used a device to send an image of Schafer's eye to Barton's location, and open the warehouse using the projection of the eye to pass a retina scanner.
The other frightened guests ran out to the streets trying to escape from Loki, but he surrounded them with a series of illusions of himself. Loki demanded that crowd kneel before him, as Loki stated that man's only purpose was to be governed.
A single man challenged him and his intentions, telling him that there have always been men like him. Loki prepared to kill the man as an example, but his attack was deflected by Captain America, sent by S.H.I.E.L.D. after having located Loki at Stuttgart.
Captain America challenged Loki, supported by a Quinjet piloted by Black Widow, who ordered Loki to surrender. Captain America fought Loki to allow the crowd to escape, but Loki proved to be superior to Rogers, barely being able to hold against Loki.
Iron Man arrived and knocked Loki down with a single shot, threatening him to fire with all his weapons if he dared to make a wrong move. Outnumbered, Loki allowed himself to be captured, secretly plotting to use this to his advantage.