She knew a great deal about the Aros and their slave system, more, probably, than any other white person in the country. Indeed few had any knowledge of them. "What is sad about the Aro Expedition," wrote Mr. Luke, one of the Cross River pioneers, "is that nearly all the town names in connection with it are unknown to those of us who thought we had a passable knowledge of Old Calabar. I never heard of the Aros, of Bende, or of Arochuku. It is somewhat humiliating that after over fifty years' work as a mission, the district on the right bank should be so little known to us." Mary had first-hand acquaintance with the people. Refugees came to her from both Ibo and Ibibio with stories of cruelty and wrong and oppression; chiefs from both regions sought her out for advice and guidance; slave-dealers from Arochuku and Bende, with their human wares, called at Ekenge and Akpap, and with many of these she was friendly, and learned from them the secrets of their trade. She told them frankly that she was coming some day to their country, and they gave her a cordial invitation, but hinted that it might not be quite safe. It was not the danger that prevented her. She would have gone before, but the difficulty was providing for Okoyong when she was absent. She would not leave her people unless they were cared for by competent hands. She asked for two ladies to be sent in order that she might be free to carry out her idea of visiting the Aro country, but none could be spared, and so she had, perforce, to wait. It was not easy, but she loyally submitted. "The test of a real good missionary," she wrote, "is this waiting, silent, seemingly useless time. So many who can distinguish themselves at home, missing the excitement and the results, get discontented, morose, cynical, and depreciate everything. Everything, however seemingly secular and small, is God's work for the moment, and worthy of our very best endeavour. To such, a mission house, even in its humdrum days, is a magnificent opportunity of service. In a home like mine a woman can find infinite happiness and satisfaction. It is an exhilaration of constant joy--I cannot fancy anything to surpass it on earth."