I am no longer in doubt.--The cause, the fatal cause of Mr Arnold's change is discovered. This miserable day has disclosed the secret to me; a black, a complicated scene of mischief. Mr Arnold rode out this morning. He told me he was to dine with a gentleman at some miles distance, and should not return till late in the evening. He was but just gone, when a lady of my acquaintance called in upon me, to request I would go with her to a play, that was to be performed at night. You must know we have had a company of players in the neighbourhood for some time past, and it was to one of those poor people's benefits that she desired my company. I promised to attend her, though you know I don't much admire those sort of entertainments in the country, and seldom go to them. The lady and her husband called upon me at the appointed hour, and I went with them in their coach. The place which the players had fitted up for their purpose, had formerly been a pretty large schoolroom, and could, with the addition of a gallery (which they had made) with ease contain above three hundred people. The play had been bespoke by some of the principal ladies in the neighbourhood, who had used all their interest for the performer, so that the house was as full as it could hold. The audience consisting chiefly of fashionable people, it was with difficulty that we reached the places which were kept for us in the pit, as they happened to be on the bench next the stage, and the door was at the other end of the house. The first object that I observed on my coming in was Mr Faulkland; he bowed to me at a distance, but made no attempts to approach me. The play was come to the latter end of the fourth act, and the curtain was let down to make some preparation on the stage, when we were alarmed with the cry of fire. It happened that the carpenters, who had been employed in fitting up this extempore theatre, had left a heap of shavings in a little place behind the stage, which had been converted into a dressing-room; a little boy belonging to the company had found a candle in it, and having piled up the shavings, set them on fire, and left them burning: the flame communicated itself to some dry boards which lay in the room, and in a few minutes the whole was in a blaze. Some persons, who heard the crackling of the wood, opened the door, when the flame burst out with such violence, that the scenes were presently on fire, and the curtain, which as I told you was dropt, soon caught it. The consternation and terror of the poor people, whose _all_ was destroying, is not to be described: the women shrieking, threw themselves off the stage into the pit, as the smoke and flames terrified them from attempting to get out any other way, though there was a door behind the stage. The audience were in little less confusion than they; for as the house was composed chiefly of wood, every one expected it would soon be consumed to ashes.