G minor, 2/4 time, sonata form.

Upon a forceful striking of the G minor tonic chord, the first theme, fierce and urgent in character, begins. The transition section already moves to the relative major (B-flat major), and the introspective second theme follows directly. The development section is primarily based on motives from the first theme.  

Although the tempo marking at the beginning of this movement is "As fast as possible (So rasch wie möglich)", at the beginning of the coda, where 16th-note unisons continue, it is marked "Faster (Schneller)", and from the point where the first theme partially recurs, it is marked "Even faster (Noch schneller)". While logically peculiar tempo indications, they align with the character of the piece, which constantly feels driven by something.