The Mackenzies continued at Seaforth until the early part of the year 1859. The work was peaceful and cheerful. There were no such remarkable successes in conversion as the Robertsons met with, probably because in the further and wilder district the work was more pioneering, and the Robertsons had never been without a nucleus of Christians, besides which the gifts of both appear to have been surpassing in their power of dealing with natives, and producing thorough conversions. Moreover, they had no cure but of the Kaffirs, whereas Archdeacon Mackenzie was the pastor of a widely scattered population, and his time and strength on Sundays employed to their very uttermost. Church affairs weighed heavily upon him; and another heavy sorrow fell on him in the death of the guardian elder sister, Mrs. Dundas. Her illness, typhus fever, left time for the preparation of knowing of her danger, and a letter written to her by her brother during the suspense breathes his resigned hope:--"Dear Lizzie, you may now be among the members of the Church in heaven, who have washed their robes and made them white in the blood of the Lamb. If so, we shall never meet again on earth. But what a meeting in heaven! Any two of us to meet so would be, more than we can conceive, to be made perfect, and never more to part." And when writing to the bereaved husband after the blow had fallen, he says: "Surely we ought not to think it strange if the brightest gems are sometimes removed from the workshop to the immediate presence of the Great King." But the grief, though borne in such a spirit, probably made him susceptible to the only illness he experienced while in Natal. The immediate cause was riding in the burning sun of a southern February, and the drinking cold water, the result of which was a fever, that kept him at home for about a month. There was at this time a strong desire to send a mission into independent Zululand, with a Bishop at its head. Bishop Colenso was at first inclined to undertake the lead himself, resigning Natal; and next a plan arose that Archdeacon Mackenzie should become the missionary Bishop. The plan was to be submitted to the Society for the Propagation of the Gospel, and for this purpose the Archdeacon was despatched to England, taking Miss Mackenzie with him; but the younger sister, Alice, having so recently arrived, and being so valuable as a worker among the natives, remained to assist in the school of young chiefs who had been gathered together by Bishop Colenso.