Spoiler Alert for Ghosts season 4, episode 6, "The Primary Source"Ghosts season 3 finale.

Despite his efforts to start anew, with Isaac letting his hair down in Ghosts season 4 and vowing to become a better person, Isaac continues to miss the mark in episode 6, "The Primary Source," with the silver lining being that the failure causes Isaac to grow and be less stubborn. After penning the ghost's biography and scoring a book deal, Rose McIver's Sam hears back from the publishers of Isaac's book. However, it's terrible news. The publishers want a copy of Sam's primary source (and the writer's source is Higgintoot himself).

Sam Continues To Fail Getting Isaac's Biography Published In Ghosts

Isaac Is Both Ghost And Vampire In Season 4

After a rocky start, publishing the book Ghosts season 4, episode 6, makes Sam and Isaac's journey worse. While Sam and Jay (Utkarsh Ambudkar) track Isaac's diary at Fort Ticonderoga to trace a primary source for Sam's Isaac biography, their efforts are for naught. Sam is aloof when the publishing company's authenticator arrives at Ghosts' Woodstone B&B, and she tells him (thinking he is one of the cholera ghosts since he dons a smock) that she's forging Isaac's diary since it didn't contain much other than Isaac's musings about sandwiches.

Isaac was devastated when he learned his Revolutionary War efforts were a literal historical footnote.

Sam's publisher understandably cuts the book deal after the mishap. While Sasappis (Romàn Zaragoza) has a fascinating alternative — pitching the book as historical fiction with Isaac as a vampire — it's far from what Isaac and Sam hoped for regarding the US Ghost character preserving his legacy. Isaac was devastated when he learned his Revolutionary War efforts were a literal historical footnote. Isaac hoped Sam could submit his complete story to history, but his story will be a fictional tale instead.

Isaac's Legacy Insecurity Will Get Worse With Alexander Hamilton's Appearance In Ghosts Season 4

Alexander Hamilton Is Coming In Season 4

Sam and Isaac's failure to tell his story is about to get worse due to Ghosts season 4 finally casting Alexander Hamilton to appear in the series, casting Nat Faxon, according to a report from TV Line. Isaac's book was an effort to bolster his sense of self due to his insecurity about his role in history. Isaac's drama begins when he first hears about Alexander Hamilton's legacy through Sam, prompting him to ask her to write the book so that he can compete with his long-time rival.

As Isaac's journey continues, Ghosts season 4 will pay off a three-year Isaac grudge by including his rival. Hamilton could appear as a ghost, causing Isaac to confront his rival directly, or he could appear in a flashback to a memory from Isaac's past. Regardless of how Hamilton appears, revisiting the character within the Ghosts story will cause Isaac to confront his failures and insecurities. Isaac and Sam's inability to publish his biography will only worsen things, since the captain could not make his mark alongside Hamilton in the official history books.

Source: TV Line