He was an advisor to U.S. President Franklin D. Roosevelt when the Allies realized that the Nazi leader Adolf Hitler was racing to use the occult to turn the tide of World War II.
Project Ragna Rok, a plan to use black magic to win the war, was put in place by the supposedly deceased mystic Rasputin.
Bruttenholm and Hellboy developed a very strong emotional bond like that of a father and son, and both joined the U.S. Government's new Bureau of Paranormal Research and Defense.
As the movie begins in the present, Broom discovers that he is dying of cancer, and selects the young agent John Myers to serve as Hellboy's new liaison.
Before he is killed, Rasputin taunts him, saying that Broom has effectively nurtured a creature with the power, and the destiny, to bring about the Apocalypse, and also shows him a vision of the post-apocalyptic remains of New York City, with the Ogdru Jahad looming overhead and Hellboy, with regenerated horns, standing in the center.
When Hellboy is about to unlock the key that will release the Ogdru Jahad from their prison as Anung un Rama, Myers stops him by throwing him a rosary that belonged to Broom, a reminder that Broom raised him to choose his own path – upon which Hellboy tears away his re-grown horns and kills Rasputin rather than turn the final key.
[citation needed] Bruttenholm only appeared in the sequel film's flashback prologue, Hellboy II: The Golden Army, played again by Hurt.
At the end of World War II, Trevor's mission was to accompany Lobster Johnson to kill Hellboy upon his arrival during the Nazis' Project Ragna Rok, but he couldn't.
In the film, a series of flashbacks (in reverse chronological order) show the young Bruttenholm traveling to Eastern Europe to combat Erzebet Andrushko, an evil vampiress who has been terrorizing Transylvania.