Jim Linton and Wally Meadows are serving in the British Army. During the beginning of the horrors of warfare in France, they come in contact with the enemy's deadly new weapon, poison gas. They spend recovering in the green countryside of Ireland with Jim's little sister, Norah, and their father, David. But this time-out spent fishing and riding across the hills brings unforeseen and dangerous drama, which they share with a new friend, the heroic Irishman, John O'Neill.
