Annie Shearer lives in the country town of Upson Downs with her best friend, an adopted stray dog called Runt. The two share a very special bond.
After years evading capture, Runt is remarkably fast and agile, perfect for herding runaway sheep. But when a greedy local landowner puts her family's home at risk, Annie directs Runt's extraordinary talents towards a different pursuit - winning the Agility Course Grand Championship at the lucrative Krumpets Dog Show in London.
However, there is a curious catch: Runt will only obey Annie's commands if nobody else is watching.
With all eyes on them, Annie and Runt must beat the odds and the fastest dogs in the world to save her farm.
Runt is a heart-warming and hilarious tale of kindness, friendship, hurdles, hoops, tunnels, see-saws, being yourself and bringing out the best in others.