In _Senior Nurse_, Cherry realizes that "a senior really must be a little more sober and responsible" - perhaps she should have warned the head nurse right away about the rabbit that had been smuggled into the pediatric ward. But the children had enjoyed it so! As "lofty" seniors, Cherry and her friends each "adopt" a probationer (first-year student) to mentor. Why did her probie have to be dull and sullen Mildred Burnham? Dr. Joe Fortune has discovered a new way to synthesize penicillin - which could make a life or death difference on the battle front. But how did word of it become common knowledge around Spencer? Cherry discovers that Mildred has more to her than she thought as together they face the dangerous thieves who have stolen Dr. Joe's formula.