Karen David Explains Grace Shocker on Fear the Walking Dead (Exclusive)

[Warning: This story contains spoilers for Fear the Walking Dead season 8 episode 5, "More Time Than You Know."] There was no saving grace on Sunday's Fear the Walking Dead. Grace (Karen David) revealed during last week's episode that she was sick, telling Morgan (Lennie James) she was "paying the price for chasing the dead." On Sunday's "More Time Than You Know" episode, Grace confirmed her terminal diagnosis: cancer. It's one that the former nuclear power plant worker feared from her very first episode in season 5, where she explained she was "exposed to more alpha emitters than most people see in a lifetime" while cleaning up the radioactive walkers killed when the plant's reactor melted down.

After seven years, the "radiation's caught up with me," Grace told Morgan, estimating she had months to a year left to live. While Grace's cancer isn't specified, she once told Morgan in the season 5 episode "210 Words Per Minute" of her expected ultrasound results: "It'll be cancer. Thyroid. Maybe in the lymph nodes." In the season 5 episode "Channel 4," Grace was spotted checking her neck for signs of cancer, but her suspected radiation sickness eventually turned out to be pregnancy

"I'm so deeply impressed that you remember that because it was in one of her tapes, where she's checking her thyroid," David told ComicBook when asked if Grace's diagnosis was thyroid cancer. "We never decided what kind of cancer it would be." David explained that Grace's cancer was intentionally "left to interpretation," adding the thyroid theory is "a good one." 

"The association between radiation exposure and the occurrence of thyroid cancer has been well documented, and the two main risk factors for the development of a thyroid cancer are the radiation dose delivered to the thyroid gland and the age at exposure," according to the U.S. Department of Health and Human Services. "The risk increases after exposure to a mean dose of more than 0.05-0.1 Gy (50-100mGy) [unit of radiation dose] ... After exposure, the minimum latency period before the appearance of thyroid cancers is 5 to 10 years." Papillary thyroid cancer, or PTC, is "the most frequent form of thyroid carcinoma diagnosed after radiation exposure."

In the end, it wasn't the radiation. After being bitten by a walker, it was a race against time to get a fever-stricken Grace to June (Jenna Elfman), whose radiotherapy treatments stop the infection from spreading. Grace's cancer meant she could be exposed to otherwise lethal doses of radiation to potentially treat the bite, giving her more time with Morgan and her daughter, Mo (Zoey Merchant).

But it was too late: Grace died from a fatal fever. Grace didn't receive the treatment in time, June explained — and even if she did, it hasn't worked on anyone else.

"I always knew that Grace was on a ticking time bomb, so to speak, right from day one, because of the nature of her storylines. We all knew that from day one when we met Grace that she had been exposed to copious amounts of radiation. So it was just a matter of when," David said. "I always thought that it would be her succumbing to her radiation. I never thought it would be through a walker bite. So that really threw me off. I was not expecting that at all. And I just thought, well, it certainly raises the stakes even more, as opposed to her just succumbing to her radiation, that now she really is on borrowed time [after the bite]."

Read our "More Time Than You Know" postmortem with Karen David.

New episodes of Fear the Walking Dead premiere Thursdays on AMC+ and Sundays on AMC. Stay tuned to ComicBook/TWD and follow @CameronBonomolo and @NewsOfTheDead on Twitter for more TWD Universe coverage.