On a knife edge

On a knife's edge is the title of a novel and several films:

On the Razor's Edge (novel) , novel by William Somerset Maugham
Auf Messers Schneide (1946) , film adaptation of the novel, directed by Edmund Goulding
On a knife's edge (1984) , film adaptation of the novel, directed by John Byrum
Dr. Kildare: On a Knife's Edge ( Dr. Kildare's Strange Case , 1940), directed by Harold S. Bucquet
Sling Blade - Razor ( Sling Blade , 1996), directed by Billy Bob Thornton
On the Razor's Edge - Rivals on the Abyss (1997), directed by Lee Tamahori
On a Razor's Edge (2003) ( Den Of Lions ), directed by James Bruce
Auf Messers Schneide (2009) , film about medical technology in Tuttlingen, directors: Sören Lauinger and Ephraim Broschkowski