It back to the primary theme, but in Db major, which is a Neapolitan of the original C major. Bar 249 to 258 is uses the Primary theme. The key in this part is from Db major to Ab major to Bb minor and to C minor. Bar 258 has a Ger+6 chord, which leads to the V in C major in bar 259. Bar 260 has a transition chord G dim. (ex.)The C# will goes to D, and the Bb will goes to B in bar 261,and build the G chord.
From the measure 261, the Primary theme is developed for the left hand; the right hand played some new elements. This section is all in C major. Bar 261 to 264 as one phrase, and bar 265 to 268 is the sequence go down a step of the first phrase. From bar 269, the right hand use the motive 2 and 3, the left hand keeps the 16th notes accompaniment. The chord progression for these three bars is: ii-vii65 dim | vii43dim-vii7dim | iii6-viidim/ii |. From bar 272 to 276, there has an ascending scale that build the climax, which is A-B-C-D-E-F-G- G#-A. These ends at IV of C major in bar 276, and goes to V 6/4 in bar 278.The V 6/4 continue till bar 282. Bar 282 to 283 has a sustained V7, which makes a HC at bar 283.
Measure 284 to 294 back to the ST. This time, not like the one in exposition or in recapitulation, it starts and ends in C major. The PAC in C major (I) is at the first beat of bar 295. From bar 295, the PT happed again, but it’s very short, and builds the ending in C