Read it through once

Against these far stretches of country rose, in front of the other city edifices, a large red-brick building, with level gray roofs, and rows of short barred windows bespeaking captivity, the whole contrasting greatly by its formalism with the quaint irregularities of the Gothic erections. It was somewhat disguised from the road in passing it by yews and evergreen oaks, but it was visible enough up here. The wicket from which the pair had lately emerged was in the wall of this structure. From the middle of the building an ugly flat-topped octagonal tower ascended against the east horizon, and viewed from this spot, on its shady side and against the light, it seemed the one blot on the city’s beauty. Yet it was with this blot, and not with the beauty, that the two gazers were concerned.