It's the summer holidays! But this year, Flo (Nico Marischka) doesn't want to be separated from Lassie: instead of spending their holidays in Gran Canaria with their parents, Flo and his loyal best friend opt to visit their Aunt Cosima’s (Katharina Schüttler) farm in South Tyrol, where she lives with Jack Russell terrier Pippa, and her foster children Kleo (Anna Lucia Gualano) and Henri (Pelle Staacken).

The adventurous pair soon find themselves in the middle of an alarming new mystery – all of the pedigree dogs in the village are disappearing! When Pippa is the next to be stolen, Lassie’s detective skills are put to the ultimate test in a tense race against time to catch the thieves, rescue Pippa, and foil the despicable dognapping scheme once and for all!