Within hours of best-selling author Julian Hartswood being cancelled for reposting a white supremacist, he discovers he has a neurodivergent son called "Austin".
Austin invites Julian and Ingrid home to have lunch with his "embarrassing" family, while Ingrid contemplates some extra-marital wham wham.
On a bonding tour with Austin, Julian starts filming a documentary about "father and neurodivergent son quality time" to spring-clean his image. But Ingrid and Austin get wise to his Machiavellian ways.
Julian's documentary capturing his growing relationship with Austin is now out in the open and Julian engages an award-winning filmmaker to finish the job. Is bringing Austin to London the perfect treat for him or for Julian?
Austin organises a bespoke celebrity bus tour while Julian contemplates hiring someone to "scrub" his image. Ingrid decides to expand her career, combining her illustrating career with writing.
When Julian gets fired from his publisher and told his remaining books are to be pulped, Austin leads the charge to break into the warehouse to rescue whatever books are left.
Ingrid discovers a former passion while Austin and Julian prepare for the first screening of the documentary, entitled: The Greatest Man I Never Knew - that will (hopefully) rebrand Julian to the world.
Julian is concerned when Austin turns his phone off and leaves the house to have some time on his own. In a boutique gallery in outer London Ingrid prepares for an exhibition of her artwork.
With Austin now bonded with his long lost father and spent time with him in the UK does he feel like his journey of discovery is over or only just begun?
