Lyndon B. Johnson is sworn in as the new President of the USA after President John F Kennedy's assassination Popperfoto/Getty Images

Hey hey, LBJ, how many times were you almost accidentally shot by the Secret Service today?

NewsFeed sometimes gives The Huffington Post a hard time, but we have to admit this is one awesome find: According to a new book, Lyndon Johnson was almost accidentally killed by a member of his Secret Service detail the night after John F. Kennedy was killed.

The book, The Kennedy Detail, purports to be the first account of the Kennedy assassination from members of the Secret Service who were working that day.

(Read TIME’s cover story on Lyndon Johnson assuming the Presidency.)

As author and former Secret Service member Gerald Blaine explains, he was guarding Johnson’s home in Washington the night after Kennedy was killed when he heard suspicious footsteps. Blaine loudly activated his submachine gun, hoping to warn the unknown figure off, but the footsteps continued. In Blaine’s account, he brought the gun to his chest and put his finger on the trigger — only to see that the man was Johnson himself.

(See pictures of how Presidents age in office.)

As Blaine tells it, he “struggled to regain his composure as the reality of what had just happened washed over him. Fourteen hours after losing a president, the nation had come chillingly close to losing another one.”

(See all of TIME’s LBJ covers.)

Had Blaine not hesitated and instead accidentally killed Johnson, the Presidency would have passed to Speaker of the House John W. McCormack, a Democratic congressman from Massachusetts. McCormack, who died in 1980 at age 88, is perhaps best-known today as the defendant in the Supreme Court case Powell vs. McCormack, in which the Court ruled that McCormack as Speaker of the House could not bar from Congress any person who had been duly elected and appointed and met all the Constitutional requirements for office. He was a supporter of American involvement in Vietnam.