A group rich aristocrats and bankers are bored with finding life too easy. Archie Roylance puts forward the idea of a challenge, by going to Scotland to poach a stag or salmon. They send landowners a challenge using the alias John McNab.

Archie Roylance is caught with a stag by Janet Raden but excepts defeat and leaves. When Professor Bandicott finds viking treasure, Sir Edward Leithen sneaks out to bag a salmon. The Gillies catch him but young Benji takes the salmon home.

Colonel Raden and his daughters make a surprise visit and expose the group has "John McNab". However when the Colonel learns Lord Claybody has employed a thousand navvies stop anybody getting in and out of his forest he agrees to help.