Little White Lies - S1.E22

The kids are covertly planning a surprise birthday party for their father. Chief Burns tells them he is heading to the docks, but actually takes a trip to the bakery for a cake, as a present for his family, thinking that they forgot his birthday. Chase discovers this to be a lie and is confounded by this. While setting up the party back home, the kids and the other Rescue Bots realize that Chase and Chief Burns are missing, and search the entire town. Eventually they discover the two trapped inside an underground mine, and save them from the flooding water and falling rocks.