Sentence:  Miraculously, the Stasi's record of Garton Ash's years in Berlin remained intact, and in his extraordinary book "The File" he recalls going back to Berlin, sifting through the material, and piecing together those years for himself. The result is a <WSD>palimpsest</WSD> of memories, observations recorded by informants and agents, and the recollections in his own diaries at that time. 
Meaning of the word marked with <WSD> tags:  Something bearing the traces of an earlier, erased form.