Season 16 of CBS' police procedural drama series is underway on Paramount+ after the 2020 conclusion of on the broadcast network.  sees the Behavioral Analysis Unit reunite to tackle a national threat of serial killers who established a broad, interconnected network during the COVID-19 pandemic lockdown. The revival includes the returns of main cast members Joe Mantegna, A.J. Cook, Aisha Tyler, Paget Brewster, Adam Rodriguez, and Kirsten Vangsness as agents Rossi, JJ, Tara, Prentiss, Alvez, and Garcia, respectively.

The new season revealed the shocking death of Rossi's wife, Krystall (Gail O'Grady), and now, another fan-favorite couple is in danger of a similar fate.

Fans took to Twitterto express their distraught reactions to the latest  from episode 4, "Pay-Per-View,", in which viewers learn JJ's husband, Will (Josh Stewart), could have cancer.

It comes as no surprise that audiences are in disbelief at the shocking turn of events, as JJ is already under enough stress at her demanding job, and the pair have a long history that includes two kids together.

Read some fan reactions below:

While it's not confirmed yet, Will's cancer diagnosis could have far-reaching affects on the BAU, who could lose JJ over the illness.

Fans will learn more when Criminal Minds: Evolution returns next Thursday, December 15, for its mid-season finale.