Lena, a German girl living in Paris, is having a bad time when WW1 breaks out.  She's sent to a concentration camp, but the French realize that, since she speaks German, she could be a wonderful spy.

This farfetched story takes the heroine to Switzerland where she has problems.  To solve them, she must marry a French officer. The military men have no choice:  he who draws the ace of hearts will marry Lena.  As it often happens, the forced marriage results in the newlyweds falling in love with each other.

Edmond T. Gréville is French and, although he claimed that the English crews were more professional, his best work (Menaces ) was made in his native country.  I Married a Spy is an implausible story. When they say the War is over, we haven't even got the feeling a war occurred.  Probably inspired by Mata-Hari, Lena's character is not really endearing, even in the "moving" final scenes.