When their son dies in France, the couple start writing postcards to urge people to protest against Adolf Hitler and the Nazi regime.

[2] In 1940, a working-class couple in World War II-era Berlin, Otto and Anna Quangel, decide to resist Adolf Hitler and the Nazis after receiving news of the death of their only son.

While in the beginning of the film the couple's marriage seems to have dried up and they are unable to console each other for the loss of their son, their shared risk and commitment brings them closer.

During three years of painstakingly gathering clues about the "Hobgoblin" (as he calls the mysterious writer of the postcards), Escherich develops an increasing respect for this elusive unknown opponent.

Because of his lack of progress, Escherich is beaten up by the obviously impatient SS senior officer and forced to summarily execute a man whom he is certain has no connection with these subversive postcards.

[6] Other crew members included cinematographer Christophe Beaucarne, production designer Jean-Vincent Puzos, and editor François Gédigier.

[8] The director dedicated the film "in memory of Otto and Elise Hampel guillotined for having written and circulated cards against the Nazi regime between 1940 and 1943."

Tara Brady of The Irish Times wrote: "Despite a terrific triumvirate of performances from Gleeson, Thompson, and Brühl, and soft lensing from cinematographer Christophe Beaucarne, Alone in Berlin is hampered by stodgy pacing, budgetary constraints, and drab interiors.

Against this, the film offers a fascinating and timely blueprint for political dissent, a methodology that connects with pamphleteering, graffiti, and memes.