Consider first the letter. The narrative text proceeds for the most part in the past tense. Introduced in the opening paragraph [1]- [3], which twice employs the deictic reference "yesterday," the narrative proceeds from [4] onwards in simple narrative structure in the past tense in which the "train of thought" is recounted: [5] "it seemed natural"; [7] "I inquired"; [8] "it was natural to assume" and so on.