After discovering that he has a sister, Lucas Bushytail sets off to London to find her. He is robbed of his possessions and gets lost in London but through perserverance and kind hearted new friends he finally arrives at the home of his Great Uncle George and the home of his sister Holly. The Hyde Park Squirrels series is set in Victorian times and follows the adventures of two Squirrels called Luke and Holly (brother and sister) who were separated when they were babies .