Loki established a hideout with the help of the S.H.I.E.L.D. agents that he had used his Scepter to take mental control of upon arriving on Earth. He had Clint Barton enlist S.H.I.E.L.D.'s enemies to his cause, amassing mercenaries, scientists, weapons and equipment to fulfill his plan of using the Tesseract to open a portal and conquer the planet.
Erik Selvig, under Loki's control, acted as the head scientist in the construction of a device to stabilize the portal, having learned from the Tesseract itself how to do it, and for the need of Iridium to complete the device. Barton, the unwilling right-hand man of Loki while under his control, asked Selvig about the Iridium, having investigated where it was located and how to obtain it. Loki asked Barton what he needed to fulfill his task, and he answered he needed a diversion, and an eyeball.