The chief feature in this brilliant passage is a piling up of the theme in stretto form (see measures 148-153).
A stretto is a net, and if one is not constantly on the watch, he is caught in its meshes.
The scena ends with a stretto, a concluding passage taken in more rapid tempo in order to enhance the effect.
One of its rules was that every fugue should have a stretto.
The first and last quartet end with a thoroughly worked-out fugue, complete with stretto and inversions.
He was thinking more of his prima donna than of Elcia when he wrote that stretto.