Clarke was one of those men to be found in great numbers in university communities who, whilst not yet in full priest's orders, was qualifying for the priesthood, wore the tonsure, and having passed his degree in arts, was preparing himself in the schools of theology for the career to which he was dedicated.

All the canons of Cardinal College were supposed to follow this course of training.
But it was not only amongst the men that self sacrifice and devotion made itself manifest.

Dr.Langton's two daughters were as forward as any in the desire to help and tend the sick, and perform such offices of pity and kindliness as lay within their power.
Their father did not oppose them, though he laid down certain rules, which they dutifully obeyed, by which he hoped to guard them from infection.

For his part, he was always foremost in the fight with disease and contagion, and wherever the need was sorest, there was he to be found.
Thus it came about that John Clarke and Stephen Radley often found themselves face to face with the fair girls, who came and went like sisters of mercy amid the poor houses crowded together in the low-lying lands without the city walls; and Anthony Dalaber, flinging himself into the crusade with his accustomed energy, found himself in almost constant attendance upon them, carrying out their orders, assisting them in their labour of mercy, and growing more ardently in love with his chosen mistress every day of his life.
But devoted workers did not always come through such an ordeal unscathed; and Dr.Langton and John Clarke sickened of the distemper almost at the same time.

Neither was grievously ill; but both were forced to give up all work, and lie quietly in bed, suffering themselves to be tended by others.
Meantime there had been a very considerable exodus of students and masters from the city, and for the time being all lectures were suspended.