In this mansion of gloom I now proposed to myself a sojourn of some weeks. Its proprietor, Roderick Usher, had been one of my boon companions in boyhood; but many years had elapsed since our last meeting. A letter, however, had lately reached me in a distant part of the country—a letter from him—which, in its wildly importunate nature, had admitted of no other than a personal reply. The MS. gave evidence of nervous agitation. The writer spoke of acute bodily illness—of a mental disorder which oppressed him—and of an earnest desire to see me... What can the reader infer to be true of Roderick Usher's character based on how his letter to the narrator is described?