KEEPING A PROMISE: A river region story

A retired soldier's farm is attacked. When his weapon is damaged the 11 year-old son is told to take is almost 2 year-old sister and escape out the hidden exit after promising to care for his sister until she can care for herself. Their parents are killed while they travel down the tunnel, so he sets off the final defences as the enemy moves in, and kills more of the attackers. He's faithful to his promise as they live through 'interesting times' while his sister learns to care for herself.