In April, 1897, Johnstone made his appearance in a new capacity. The dispute between Greece and Turkey over the treatment of the Christians in Crete had reached an acute stage and war was expected to break out at any moment. The _Manchester Guardian_, more than any other English newspaper, had championed the Greek cause. Naturally the proprietors wished to secure the best and fullest accounts of the operations and to have them despatched in advance of other papers. Mr. J. B. Atkins was chosen to accompany the army in the field, and Johnstone's knowledge of modern languages and acquaintance with Eastern Europe marked him out as a valuable colleague. He was posted at Athens to receive reports from the front, to arrange all the details connected with their transmission, and to review the progress of the war, work which he carried through very successfully. His gift of tongues, which once caused him to be congratulated in Germany on "speaking English so well," enabled him soon to get a working knowledge of modern Greek; he was fortunate too in finding a Greek gentleman, who, grateful for the attitude of the _Manchester Guardian_, acted as his interpreter and showed him about the city. The same friend was on intimate terms with the Royal family, and introduced Johnstone to the King and the Duke of Sparta. At the close of his stay at Athens, he hesitatingly asked if there was any return he could make for the various kindnesses he had received, when this friend of royalty named so modest a fee that Johnstone was staggered; "it was the pourboire of a head-waiter," he said afterwards when describing the incident, adding that he had never realised what true democracy meant until then. Among his associates there was the correspondent of a Viennese paper who had somehow incurred the dislike and suspicion of the war-party, but, as Johnstone thought, unjustly. At last his life was openly threatened; there was no hope for him unless he managed to leave the country at once, and even then there was a fair chance that he might never reach the ship alive. Johnstone, being on good terms with the patriotic party, pleaded for his life and undertook to get him away; he cycled behind him for the four miles from Athens to the Piræus, and when they reached the harbour kept the mob off until he was safely on board an Austrian Lloyd steamer. The ride was an exciting one, for it was expected that an attempt would be made to shoot the obnoxious correspondent on the way down to the port; some shots were actually fired, but went wide of the mark. When the war was nearing the end Johnstone's services were not so necessary at Athens, and he went to join Mr. Atkins in camp; but he saw no fighting, for the day after his arrival peace was declared. His colleague returned to England, and Johnstone spent some weeks in Crete to investigate the stories of those atrocities which had been the immediate cause of the war. He went _sac au dos_ like J. K. Huysmans in 1870, but unlike him, roughed it with good humour and looked upon hardships of this kind as a helpful and valuable experience. A year later when congratulating a friend, who was somewhat habit-ridden, on his marriage, he wrote, "The problem of changing one's habits is emphatically one of those to be solved '_ambulando_.' The forms of ambulation best adapted to the purpose are serving on a campaign, doing time 'with,' and getting married;" admitting, however, that the last, though less drastic, was more permanent in its effect.