According to reports, Harry and his wife Meghan Markle have cinched a deal that puts them on the hook to deliver four books.
As far as juicy secrets go, the Palace better prepare for their most succulent squeeze.
“This book is going to make the Oprah interview look like the tip of the iceberg," a source revealed. "Harry is not getting a $15 million advance just because of who he is, he is getting it because he is going to tell everything."
That might be the only story she'll be able to read from her grandson because Harry's second book won't reportedly come out until after the Queen dies.
Meghan is also getting in on the action, just months after her debut book failed to make the Best Seller's list following plagiarism allegations.
The Duchess of Sussex is reportedly set to write a "wellness" guide after opening up about her mental health struggles during her time as a core member of the royal family.
The fourth book's subject is currently unknown.
According to Daily Mail, Harry negotiated the lucrative deal with publishers vying to work with the couple.
"He conducted negotiations – he had a very 'take it or leave it' attitude," a source tells the outlet.
Harry's reported starting price for the four-book deal was $25 million, but the final figure allegedly rang in somewhere close to $40 million.
"The final contract was actually for a four-book deal, with Harry writing one 'when his granny dies.' Meghan will write a wellness-type book and people are unsure what the fourth will be. But what is most shocking, frankly, is Harry's suggestion that the second book won't be published until the Queen is no longer here," their insider reveals.
Harry's decision to wait until his grandma's death might lead to some questions.
"People [will] start asking 'what has he got, who is he going to target?' The very idea of this unexploded bomb, hanging about waiting for the Queen to pass, is just extraordinary and may strike many as being in very bad taste," the source points out.
“Any statements or claim that is deemed to be misleading or false will no longer be met with silence,” a Palace insider told us. “It was a mistake to turn the other check after the Oprah interview, that will not happen again. Harry needs to know that he is entitled to his own feelings but not his own facts.”