Braun is first seen during Bond's arrival at Piz Gloria under the alias of Sir Hilary Bray. After rolling out a red carpet, he proceeds to help Fraulein Bunt and "Bray" out of the helicopter. Looking at the guard's sidearm, Bond comments "Fraulein, I should warn you guns make me very nervous." To which Bunt attempts to reassure the apparently nervous genealogist.
Later in the film, with Felsen, he accompanies Bunt in her pursuit of the escaping Bond through the Swiss village of Lauterbrunnen. Tracking him to a shed filled with bells, both men brawl with the spy, but are overpowered by him. Although knocked out by Bond, the pair are woken up by Bunt in order to continue the pursuit.
Escaping, 007 attempts to mingle in with the crowds near the village Ice Rink. As Braun and Bunt close in on him, he is approached by Tracy, who leads him to her car. Realizing that Bond has evaded them, the thugs return to their car and set off in pursuit, almost killing the spy as he attempts to use a phone-box to communicate with London.
In an attempt to evade them, Bond and Tracy veer into the middle of a stock car race. As expected, Bunt and her men follow and carnage ensues. Sitting in the front passenger seat of the car, Braun manages to get a few potshots at Bond's car before his own car is toppled. The vehicle's occupants are forced to abandon the burning car before it explodes.
Later, Braun takes part in the shooting at Piz Gloria where he is shot to death by James Bond, a little time after the dead of Grunther.