Now that the Great War has begun, Ruth and Helen take time off from their sophomore year at Ardmore College in order to devote their time to the Red Cross and the war effort. Ruth feels very strongly that their work is needed. Many people in the farming communities have yet to awaken to the seriousness of the war. Ruth and Helen travel to different farms and enlighten people about the work of the Red Cross.

The girls are worried, yet proud, when Tom Cameron, who is now a soldier, departs for Europe. Soon, both Jennie Stone and Helen Cameron leave for Europe so that they, too, can help out.

Ruth continues her work at home with the Red Cross and is soon transferred to the state headquarters. Ruth is concerned when she discovers that a woman, Mrs. Mantle, who had previously been very critical of the Red Cross, now works for the Red Cross in an important position.

A mysterious fire wipes out all of the records of donations at the state headquarters, and Ruth wonders whether the fire was set in order to hide any evidence of missing money. Ruth soon travels to France and helps comfort the injured soldiers. Ruth's worries surface again when Mrs. Mantle arrives in France along with two of her confederates. Ruth keeps a watchful eye on Mrs. Mantle as she wonders whether she should tell someone about her suspicions.