Pepys and his wife Jane had asked some friends to dinner on Sunday, September 2nd, 1666.They were up very late on the Saturday evening, getting everything ready for the next day, and while they were busy they saw the glow(微弱的光) of a fire start in the sky. By 3 o'clock on the Sunday morning, its glow had become so bright that Jane woke her husband to watch it. Pepys slipped on his dressing-gown and went to the window to watch it. It seemed fairly far away, and after a time he went back to bed. When he got up in the morning, it looked, though the fire was dying down, as though he could still see some flames. So he set to work to tidy his room and put his things back where he wanted them. While he was doing this, Jane came in to say that she had heard the fire was a bad one hundreds of houses had been burned down in the night and the fire was still burning. Pepys went out to see for himself. He went to the Tower of London and climbed upon a high part of the building so that he could see what was happening. From there, Pepys could see that it was, indeed, a bad fire and that even the houses on London Bridge were burning. The man of the Tower told him that the fire had started in a baker's.shop in Pudding Lane(小巷) the baker's house had caught fire from the over-heated oven(烤箱) and then the flames had quickly spread to the other houses in the narrow lane. So the Great Fire of London, a fire that lasted nearly five days, destroyed most of the old city and ended, as it is said, at Pie Comer. What is the passage about?