Six year old William, with the help of his pet frog, Filo, are regularly to be found on the 'naughty step' but their adventures are only just beginning when William takes a book from a bookcase to reveal a secret passageway which leads him back in time to London in 1874. William makes friends with a climbing boy, Feather, who shows him a glimpse of Victorian life. Filo can't help but cause mischief getting William into more trouble. William is led from an upper class mansion through the streets of London to a Victorian school. Eventually he is brought back to 'the naughty step' when he leaves the school room making him realise that maybe his school isn't so bad after all. Throughout the book the readers have to find Victorian artefacts that appear on most pages thus extending their Victorian knowledge. After his adventure William researches his Victorian history producing his 'worth knowing' facts. The readers get to extend their learning by deciding whether the facts are true or false. In subsequent books William goes back in time to other periods in history relevant to the various Key Stages. He is an actor in the Company of William Shakespeare in Elizabethan times. He is a servant in the kitchen to Henry VIII, a gladiator in Roman times, part of the ambulance crew in WWII and so on. In each book, artefacts of the era need to be found within the pictures and there is also a present day object that should not be in one of the pictures so that the children learn by comparison.