The king, however, still had patience; but a fresh imprudence of Mary's at last led to the terrible catastrophe that, since the queen's liaison with Bothwell, some had already foreseen.
Towards the end of the month of October, 1566, while the queen was holding a court of justice at Jedburgh, it was announced to her that Bothwell, in trying to seize a malefactor called John Elliot of Park, had been badly wounded in the hand; the queen, who was about to attend the council, immediately postponed the sitting till next day, and, having ordered a horse to be saddled, she set out for Hermitage Castle, where Bothwell was living, and covered the distance at a stretch, although it was twenty miles, and she had to go across woods, marshes, and rivers; then, having remained some hours tete-a-tete with him, she set out again with the same sped for Jedburgh, to which she returned in the night.
Although this proceeding had made a great deal of talk, which was inflamed still more by the queen's enemies, who chiefly belonged to the Reformed religion, Darnley did not hear of it till nearly two months afterwards--that is to say, when Bothwell, completely recovered, returned with the queen to Edinburgh.
Then Darnley thought that he ought not to put up any longer with such humiliations.

But as, since his treason to his accomplices, he had not found in all Scotland a noble who would have drawn the sword for him, he resolved to go and seek the Earl of Lennox, his father, hoping that through his influence he could rally the malcontents, of whom there were a great number since Bothwell had been in favour.

Unfortunately, Darnley, indiscreet and imprudent as usual, confided this plan to some of his officers, who warned Bothwell of their master's intention.
Bothwell did not seem to oppose the journey in any way; but Darnley was scarcely a mile from Edinburgh when he felt violent pains none the less, he continued his road, and arrived very ill at Glasgow.

He immediately sent for a celebrated doctor, called James Abrenets, who found his body covered with pimples, and declared without any hesitation that he had been poisoned.

However, others, among them Walter Scott, state that this illness was nothing else than smallpox.
Whatever it may have been, the queen, in the presence of the danger her husband ran, appeared to forget her resentment, and at the risk of what might prove troublesome to herself, she went to Darnley, after sending her doctor in advance.