Educational series for four- to seven-year-old children with learning difficulties, offering teachers, parents and carers a range of approaches to develop language and communication skills. Justin, Jack and Jack's teacher are walking up Mount Snowdon. On their travels they must find three things: a path, a lake, and the top of the mountain. Mr Tumble is on a walk in the mountains as well, and he has brought his toy duck with him. He wants to take it swimming.