Returning to Pipley following her FANY (First Aid Nursing Yeomanry) training, Olive is eager to step up her involvement in the war effort. Her pigeons are being conscripted to aid the Belgian resistance, and it's up to Olive to choose the best birds for the mission. To protect the secrecy of their work, she must also continue the ruse of being romantically involved with her superior, Captain Jameson Aldridge, a task made more challenging by the fact that she really does have feelings for the gruff Irish intelligence officer.