The Lost Sketchbook of Guillermo del Toro:

Filmmaker Guillermo del Toro put all his ideas for `Pan’s Labyrinth’ in a notebook — then lost it.

The heavyset man ran down the London street, panting, chasing the taxi. When it didn’t stop, he hopped into another cab. “Follow that cab!” he yelled. Guillermo del Toro wasn’t directing this movie. He was living it. And it was turning into a horror tale.

The Mexican filmmaker keeps all of his ideas in leather notebooks. And Del Toro had just left four years of work in the back seat of a British cab. Unlike in the movies, though, Del Toro couldn’t catch the taxi. Visits to the police and the taxi company proved equally fruitless.

Del Toro’s films — “Chronos,” “The Devil’s Backbone,” “Blade II,” “Hellboy” — typically feature magical realism. Fate was about to return the storytelling favor.

The cabbie spotted the misplaced journal. Working from a scrap of stationery that didn’t even have the name of Del Toro’s hotel (just its logo), the driver returned the book two days later. An overwhelmed Del Toro promptly gave him an approximately $900 tip.

The sketches and the ideas in that misplaced journal — four years of notes on character design, ruminations about plot — were the foundation of “Pan’s Labyrinth,” a child’s fantasy set in the wake of the Spanish Civil War.

The director, who at the time wasn’t even sure he’d actually make “Pan’s Labyrinth,” took the cabbie’s act as a sign, and plunged himself into the movie.