Mary was, at the time of these occurrences in the little room marked _C_, which was built within one of the round towers which form a part of the front of the building, and which are very conspicuous in any view of the palace of Holyrood.[G] This room was on the third floor, and it opened into Mary's bed-room, marked _B._ Darnley had a room of his own immediately below Mary's. There was a little door, _d_, leading from Mary's bed-room to a private stair-case built in the wall. This stair-case led down into Darnley's room; and there was also a communication from this place down through the whole length of the castle to the royal chapel, marked _Ch_, the building which is now in ruins. Behind Mary's bed-room was an ante-room, _R_, with a door, _o_, leading to the public stair-case by which her apartments were approached. All these apartments still remain, and are explored annually by thousands of visitors. [Footnote G: See view of Holyrood House, page 114 and compare it with this plan.] It was about seven o'clock in the evening that the conspirators were to execute their purpose. Morton remained below in the court with his troops, to prevent any interruption. He held a high office under the queen, which authorized him to bring a force into the court of the palace, and his doing so did not alarm the inmates. Ruthven was to head the party which was to commit the crime. He was confined to his bed with sickness at the time, but he was so eager to have a share in the pleasure of destroying Rizzio, that he left his bed, put on a suit of armor, and came forth to the work. The armor is preserved in the little apartment which was the scene of the tragedy to this day. Mary was at supper. Two near relatives and friends of hers--a gentleman and a lady--and Rizzio, were with her. The room is scarcely large enough to contain a greater number. There were, however, two or three servants in attendance at a side-table. Darnley came up, about eight o'clock, to make observations. The other conspirators were concealed in his room below, and it was agreed that if Darnley found any cause for not proceeding with the plan, he was to return immediately and give them notice. If, therefore, he should not return, after the lapse of a reasonable time, they were to follow him up the private stair-case, prepared to act at once and decidedly as soon as they should enter the room. They were to come up by this private stair-case, in order to avoid being intercepted or delayed by the domestics in attendance in the ante-room, _R_, of which there would have been danger if they had ascended by the public stair-case at _T_.