Returning from Ikpe on one occasion in 1911, she found that a tornado had played havoc with the Use house, and immediately set to, and with her own hands repaired it. The strain was too great for her enfeebled frame, and symptoms of heart weakness developed. She had nights of high fever and delirium, and yet so great was her power of will, that she would rise next day and teach and work, while on Sundays she took the services, although she was unable to stand. "I had a grand day," she would say, "notwithstanding intense weakness."

Dr. Robertson of Itu had gone home on furlough, and there came to take his place, Dr. Hitchcock, a young, eager, clear-headed man, as masterful in his quiet way as "Ma." He had proposed going to China in the service of the Church, but agreed meanwhile to put in a year at Itu. She watched him for a time with growing admiration, and saw the curiosity of the natives turn rapidly to confidence, then to appreciation, then to blind devotion and worship. When she looked at the great crowds flocking day after day to the dispensary and hospital, she thought of the scene of old when the poor and the halt and the maimed gathered round Christ. "A rare man," she said, "a rare Christian, a rare doctor. A physician for soul and body. I am beginning to love him like a son." And like a son he treated her. Although he had scarcely a minute to spare from his work, he ran up every second day to Use to study her. He believed that she was not being nourished. That there were grounds for his suspicions her own diary records. There was money for her in Duke Town, she had often cheques lying beside her, but it was not always easy to obtain ready cash, and sometimes she ran short. On June 14 she wrote:

Market Morning.—Have only 3d. in cash in the house; sent it with 2 Ikpats (the first Efik schoolbook) and New Testament to buy food, and sold all 3 books for 6d. Got 5 small yams, oil, and shrimps, with pepper and a few small fresh fish.

It was on the following morning as early as six o'clock that the doctor called to examine her again. His decision was that she was not to go to Ikpe, she was not to cycle, she was to lie down as much as possible. She laughed, and on the Sunday went to church and conducted two services; but she almost collapsed, and when the doctor came next day he ordered her to take to her bed, and not go to any more meetings until she obtained his permission. Mary had at last met her equal in resolution. "He is very strict," she confessed, "but he is a dear man. Thank God for him."

A trip to Ikpe which she had planned for the Macgregors had to be cancelled, and they decided to go to Use instead, and aid and abet the doctor in his care of her. She got up to receive them, and then wrote, "The doctor has sent me back to bed under a more stringent rule than ever. Very stern. I dare not rise." "You must eat meat twice a day," the doctor said. "I'm not a meat eater, doctor," she rejoined. His reply was to send over a fowl from Itu with instructions as to its cooking. "Why did you send that fowl, doctor?" she asked next day, "Because it could not come itself," was all the satisfaction she got. It was not the first fowl that came from Itu—the next came cooked— while the Macgregors telegraphed to Duke Town for their entire stock. "What a trouble you dear folk take," she sighed.

"You will have to go to Duke Town for a change," suggested the doctor one day. "Na, na," she replied; "I've all my plans laid, and I cannot draw a salary and not do what I can." "You have done so well in the past," remarked Mr. Macgregor, "that you need not have any qualms about that." "I've been paid for all I've done," was her retort. But the doctor insisted, and the very thought of leaving the station and the household work unattended to, put her in a fever. "Of course," she said, "to the doctor my health is the only thing, but I can't get rest for body while my mind is torn about things. He is vexed, and I am vexed at vexing him."

Not satisfied with the progress she was making, the doctor transferred her to Use, where she was under his constant observation. "Life is hardly worth living," she complained, "but I'm doing what I can to help him to help me, so that I can be fit again for another spell of work." That was her one desire, to be well enough to go back to the bush. A messenger from Ikpe came down to find out when she was returning. "Seven weeks," was the doctor's firm reply. "I may run up sooner than that," was hers. "I'm quite well, if he would only believe it."

But it was well on towards the end of the year before she was, in her own words, out of the clutches of the "dearest and cleverest and most autocratic Mission doctor that ever lived." She literally ran away, and was up at Ikpe at once, exultant at having the privilege of ministering again to the needs of the people. There was a throng at the beach to welcome her. She was soon as busy as she had ever been, though she was usually carried now to and from church and other meetings. Jean she placed at Nkanga as teacher and evangelist, the people giving her 1s. per week and her food, and "Ma" providing her clothes. It was astonishing to her to see how she had developed. An insatiable reader, she would place a book open anywhere in order that she might obtain a glimpse of the words in passing, reminding "Ma" of her own device in the Dundee weaving-shed. Her knowledge of the Bible was so thorough and correct that the latter considered her the best Efik teacher she knew. Soon she gathered about her some two hundred men and women from the upper Enyong farms, who were greatly pleased with her preaching. She came over to Ikpe for Christmas, the first the household had spent in that savage land, and there was a service in the church, which was decorated with palms and wreaths of ferns. Mary told the story of Bethlehem, and the scholar lads, of their own accord, marched through the town singing hymns…. About this time Miss Slessor rendered important service to the Mission by her testimony before an Imperial Government Commission, which had been sent out to Investigate the effects of the import, sale, and consumption of alcoholic liquor in Southern Nigeria. She provided very convincing evidence of the demoralisation caused through drink, but with keen intuition she felt that little would come of the "palaver," and she was right.