After hearing the gunshot, Kate, Steve Rogers's neighbor ran to Nick Fury's body. -I am S.H.I.E.L.D.'s Agent 13, Fury sent me to keep an eye on you. Now I'll keep an eye on him. You go after the killer!!! - Agent 13 said. Captain Steve Rogers ran through the window after the mysterious killer. Cap threw his shield at the masked man, but he grabbed it in the air and threw it back at its owner. When Cap tried to follow him through the buildings, he was nowhere to be seen. -What did the assassin look like? - Romanoff asked Cap. -He was strong... He was fast... And had a metal arm. - Rogers replied.