|For other uses, see Blitzkrieg Button (disambiguation)|
Twelve vials of blood were taken from Steve Rogers after the Assassination of Abraham Erskine, because the formula of the Super Soldier Serum was lost after Erskine's assassination. While the U.S government kept eleven, Howard Stark was entrusted with one of the vials.
Stark returned to New York City and asked Carter to do an inventory of the inventions that the New York Bell Company branch of the Strategic Scientific Reserve had confiscated from The Heartbreak that had previously been stolen from him by Leet Brannis. He gave Carter a Camera Pen to secretly take pictures to see if the Blitzkrieg Button was among those items.
When Carter returned with the photographs and Stark developed them, Stark told Carter a lie that the Blitzkrieg Button was created to hide London from attacks from Germany during World War II. He said that it caused a city-wide blackout; he hoped that Carter could retrieve the device before someone accidentally activated it and caused such a blackout in New York City. Stark gave Carter a dummy to replace the Blitzkrieg Button so that its disappearance would go unnoticed.
On her way to retrieve the device, Carter discussed the device with Edwin Jarvis; she noted that each time Jarvis told a lie, he would tug his ear. This made Carter suspect that the Blitzkrieg Button was more than she was being told.
Carter retrieved the device from the laboratory of scientist Alex Doobin. However, curiosity got the best of her and she pressed a button on the device; it opened to reveal a vial of blood inside.
Carter took the Blitzkrieg Button to her apartment in the Griffith Hotel where Stark was hiding from law enforcement. She asked him what was inside; when Howard revealed it contained Steve Rogers' blood, she hit him, giving him a black eye.
Stark explained to Carter that he wanted Rogers' blood because it may be a panacea that could even cure the common cold; Carter, visibly upset, said that she knows that Stark wants the blood to make money. She decided that she was tired of compromising her principles for Stark.
Later, that evening, Carter created a hole in the wall of her apartment and placed the Blitzkrieg Button with the vial of blood within it inside the hole.
Days later, Carter returned to that hole and grabbed the Blitzkrieg Button; she was on the run from the SSR and did not want the object found. She stuffed it within her purse.
Carter was captured when she was rendered unconscious. Daniel Sousa grabbed her purse. When Carter was brought to the interrogation room of the New York Bell Company Office, evidence of Carter's crimes was displayed, including an incriminating photograph and the Blitzkrieg Button.
Daniel Sousa kept the Blitzkrieg Button on the desk during the interrogation of Peggy Carter. In order to gain the trust of her fellow agents, Carter allowed Chief Roger Dooley to open the device and hold the vial containing Steve Rogers' blood.
Later, Carter and the other agents wondered what Ivchenko wanted; Carter hurried to the laboratory to see if the device was still there. She felt relief when it was.
Edwin Jarvis stole the vial of blood from within it and gave it to Carter to keep it safe.
Carter poured the blood into the water over the Brooklyn Bridge.