In the book, more of a focus is given to Amy’s origins and the time she spent with her mom. Cronin’s novel gives Amy’s mom a tragic backstory and explains what led her to abandon her daughter (rather than Amy feeling responsible for her mother’s death like she does on the show), which leads to another change —
Amy lives at a convent in the book
Instead of living with a less-than-friendly foster family, Amy lives in a convent in the book until Wolgast comes to get her.
Lacey was still a nun
Another surprising character change is that of Lacey Antoine. On the show, Lacey is ex-military and has a history with Wolgast. That’s not the case in the book. In the book, Lacey (unwillingly) turns Amy over to Wolgast and then follows them to NOAH’s headquarters, where she becomes part of the action.
Shauna Babcock is a man
Shauna Babcock is one of the most interesting characters on the Fox program, but in the book, she’s not a Shauna so much as a Shaun. Though the crime committed is the same, the book’s Giles Babcock was also known for being constantly chatty, which was unnerving when he became infected. (Sykes’ gender was also changed for the TV adaptation).
The group is attacked by bats in Bolivia rather than a viral
The original expedition in the books was definitely larger than the one depicted on the show, and the catalyst for the impending apocalypse was changed significantly from the source material for the show. Rather than keeping Cronin’s bats (the bat-bites changed Fanning to NOAH’s Patient Zero), the show opted to go with Fanning being bitten by a man infected with the virus in Bolivia.
Lear’s wife is dead
One of the biggest changes from book to screen involves Jonas Lear’s wife. On the show, much of Lear’s motivation for what he does at Project NOAH was to save her from her fate rather than watching her succumb to Alzheimer’s; in the book, Liz is already dead and Lear starts NOAH in her memory. Liz being alive (and being infected) complicated things in a pretty major way on the show, though it seems to have ended in her death all the same.
Shifting character focus
If you’ve been keeping up with the show, you’ll remember the “good” janitor who Babcock decidedly didn’t kill — a janitor named Grey. In the book, Grey is definitely more of a presence than he is on the show (and definitely less of a nice guy); a convict now working for NOAH, he gets a role in the plot. On the show, Grey hasn’t been much of a character outside the episode where Babcock spared his life.
In addition, Wolgast’s ex-wife, Lila, barely exists in the book, whereas on the show, she has been a major influence and contributes to the plot.
A huge time jump
One of the major concerns fans had about a The Passage adaptation was the time jump midway through the book. In the novel, the story jumps forward 100 years after the virals break out of the compound and focuses on a new group of survivors. It’ll remain to be seen whether this is the case on the show.
[Warning: Contains potential spoilers for The Passage, in both its novel and TV show forms.]
As with any book-to-TV adaptation, some things have been changed from Justin Cronin's novel to Fox's hour-long weekly installments of The Passage.
Characters have been resurrected, given larger roles and gender-swapped. Some backstories have been changed or modified. And — perhaps most importantly to book fans — a pretty big twist is coming that the show will either need to ignore or find a way to translate to screen.
Click through the gallery above to read about some of The Passage's most notable changes from the source material.