In the latest instalment of the adventures of Poland’s favourite four-legged friend, the titular character disappears under mysterious circumstances, and his loved ones, together with a new dog, set off in search of him.

Based on a true story. Two brothers, Artur (22) and Marcin (12), murder their own mother. The film starts with the boys' arrest and then takes us through the last 12 months in a series of flashbacks.

The life of Zuzia, whose dad works on the railway, changes massively when Lampo, an extraordinary travelling dog, joins the family. The remarkable shepherd dog, whose train trips are an internet sensation, immediately becomes the best friend of the girl suffering from a heart condition.