What is the main conflict in Flashman and the Redskins by George MacDonald Fraser?

Flashman and the Redskins is, the seventh installment of the "Flashman Papers" supposedly discovered late in the 20th century and published by George MacDonald Fraser, detailing Sir Harry Flashman's fantastic career. This volume continues Flashy's American adventures in two parts: the 1849/50 gold rush and an 1875/76 vacation that takes Flashy to Little Bighorn and a surprise meeting with his illegitimate son.