If this is an adventure, we should just plunge in... When thirteen-year-old cousins Ivan and Daphne go on a treasure hunt in the rain one summer day, they never expect to stumble into a whole new world where words and numbers run wild. After the cousins outwit a plague of punctuation, grateful villagers beg them to find Lexicon's missing children, who have been enticed away by dancing lights in the sky. Trekking between villages in search of clues, the cousins encounter a talking thesaurus, a fog of forgetting, the Mistress of Metaphor, a panel of poets, feuding parts of speech, and the illogical mathematicians of Irrationality. When a careless Mathemystical reflects them across the border into the ominous Land of Night, their peril deepens. Kidnapped, imprisoned, and mesmerized--with time running out--will Ivan and Daphne find a way to solve the mystery of the lights in the sky and restore the lost children of Lexicon to their homes? Lost in Lexicon will whisk children away into an interactive and magical world of learning.