Burying himself in research with long-time researcher Dick Susskind (Alfred Molina) and European artist wife Edith (Marcia Gay Harden), Irving starts to build a mountain of lies, reaching a point where the fraud takes on a life of its own, and even he becomes dangerously close to believing his lies. Only Irving's mistress, Nina van Pallandt (Julie Delpy), seems to realize the danger of his scheme.

But, the media falls for Irving's tune, with Life magazine publishing excerpts of Hughes' "memoir." He had never met Hughes, but the hoax was so convincing it fooled handwriting experts and people who had known Hughes – even an ex-associate of Hughes thought the letter was from the recluse himself. Meanwhile, Irving's neglected wife deposits the $1 million advance check into a Swiss bank account.

Director Lasse Hallstrom and screenwriter William Wheeler (working from Irving’s memoir) adapt Irving's memoir of the scam with many fictionalized events for cinematic effect, creating a subplot that suggests that Hughes was a puppetmaster pulling Irving's strings.