Luke Burgoa is an ex-Marine on a solitary covert mission to infiltrate the Basque separatist organization ETA in Spain and help bring down its military commander, Peru Madariaga. Luke's orders are to sell guns to the ETA and lure Peru into a trap. Instead he falls in love with Peru's estranged wife, Ysolina. Sins of the Younger Sons is a love story exposed to dire risk at every turn.