After a mysterious explosion over Victorian London, Cummerbund Bandersnatch (a likeable, if dim-witted twit) visits his uncle's laboratory and discovers an experimental new formula guaranteeing a "good time" for whoever drinks it. Seduced by the promises in his uncle's journal, Cummerbund decides that it is probably safe to drink and discovers his life will never be the same again.

What may seem like a curse at first, leads Bandersnatch on a thrilling, love-torn adventure through the back alleys of Old London Town as he uncovers a sinister plot involving a secret society, the royal family, copious amounts of dog hair and his uncle at the very centre.