Meanwhile the conspiracy proceeded, and Douglas and Ruthven, having collected their accomplices and taken their measures, came to Darnley to finish the compact. As the price of the bloody service they rendered the king, they exacted from him a promise to obtain the pardon of Murray and the nobles compromised with him in the affair of the "run in every sense". Darnley granted all they asked of him, and a messenger was sent to Murray to inform him of the expedition in preparation, and to invite him to hold himself in readiness to reenter Scotland at the first notice he should receive. Then, this point settled, they made Darnley sign a paper in which he acknowledged himself the author and chief of the enterprise. The other assassins were the Earl of Morton, the Earl of Ruthven,,George Douglas the bastard of Angus, Lindley, and Andrew, Carew. The remainder were soldiers, simple murderers' tools, who did not even know what was afoot. Darnley reserved it for himself to appoint the time.
Two days after these conditions were agreed upon, Darnley having been notified that the queen was alone with Rizzio, wished to make himself sure of the degree of her favour enjoyed by the minister. He accordingly went to her apartment by a little door of which he always kept the key upon him; but though the key turned in the lock, the door did not open. Then Darnley knocked, announcing himself; but such was the contempt into which he had fallen with the queen, that Mary left him outside, although, supposing she had been alone with Rizzio, she would have had time to send him away. Darnley, driven to extremities by this, summoned Morton, Ruthven, Lennox, Lindley, and Douglas's bastard, and fixed the assassination of Rizzio for two days later.
They had just completed all the details, and had, distributed the parts that each must play in this bloody tragedy, when suddenly, and at the moment when they least expected it, the door opened and, Mary Stuart appeared on the threshold.
"My lords," said she, "your holding these secret counsels is useless.
I am informed of your plots, and with God's help I shall soon apply a remedy".
With these words, and before the conspirators hid had time to collect themselves, she shut the door again, and vanished like a passing but threatening vision. All remained thunderstruck. Morton was the first to find his tongue.
"My lords," said he, "this is a game of life and death, and the winner will not be the cleverest or the strongest, but the readiest.
If we do not destroy this man, we are lost. We must strike him down, this very evening, not the day after tomorrow."
Everyone applauded, even Ruthven, who, still pale and feverish from riotous living, promised not to be behindhand. The only point changed, on Morton's suggestion, was that the murder should take place next day; for, in the opinion of all, not less than a day's interval was needed to collect the minor conspirators, who numbered not less than five hundred.
The next day, which was Saturday, March 9th, 1566, Mary Stuart, who had inherited from her father, James V, a dislike of ceremony and the need of liberty, had invited to supper with her six persons, Rizzio among the number. Darnley, informed of this in the morning, immediately gave notice of it to the conspirators, telling them that he himself would let them into the palace between six and seven o'clock in the evening. The conspirators replied that they would be in readiness.
The morning had been dark and stormy, as nearly all the first days of spring are in Scotland, and towards evening the snow and wind redoubled in depth and violence. So Mary had remained shut up with Rizzio, and Darnley, who had gone to the secret door several times, could hear the sound of instruments and the voice of the favourite, who was singing those sweet melodies which have come down to our time, and which Edinburgh people still attribute to him. These songs were for Mary a reminder of her stay in France, where the artists in the train of the Medicis had already brought echoes from Italy; but for Darnley they were an insult, and each time he had withdrawn strengthened in his design.
At the appointed time, the conspirators, who had been given the password during the day, knocked at the palace gate, and were received there so much the more easily that Darnley himself, wrapped in a great cloak, awaited them at the postern by which they were admitted. The five hundred soldiers immediately stole into an inner courtyard, where they placed themselves under some sheds, as much to keep themselves from the cold as that they might not be seen on the snow-covered ground. A brightly lighted window looked into this courtyard; it was that of the queen's study: at the first signal give them from this window, the soldiers were to break in the door and go to the help of the chief conspirators.
These instructions given, Darnley led Morton, Ruthven, Lennox, Lindley, Andrew Carew, and Douglas's bastard into the room adjoining the study, and only separated from it by a tapestry hanging before the door. From there one could overhear all that was being said, and at a single bound fall upon the guests.
Darnley left them in this room, enjoining silence; then, giving them as a signal to enter the moment when they should hear him cry, "To me, Douglas!" he went round by the secret passage, so that seeing him come in by his usual door the queen's suspicions might not be roused by his unlooked-for visit.