"Criminal Minds" season 10 spoilers reveal that the cliffhanger text message that Hotch received at the finale episode last season is very important, as Jennifer Love Hewitt's Kate Callahan will reportedly fit right in with the BAU team.

Thomas Gibson (Aaron Hotchner) said teased "Criminal Minds" season 10 spoilers to E! News when he promised that the message his character received at the end of season 9 will be very revealing.

"You'll find out what it says and it's important," he said.

Meanwhile, the official "Criminal Minds" season 10 spoilers by CBS reveal what's in store for BAU and Jennifer Love Hewitt.

"The BAU team investigates a series of murders in Bakersfield, Calif., which have left the victims unidentifiable. Also, the team welcomes new agent Kate Callahan (The Client List's Jennifer Love Hewitt) into the BAU fold," the synopsis reads.

Kate Callahan is an undercover agent from the FBI who was transferred to the Behavioral Analysis Unit due to her stellar work.

Showrunner Erica Messer earlier sad in a statement "We're thrilled to introduce a new special agent by adding the very talented Jennifer Love Hewitt to our amazing cast. Many of us on the show have enjoyed working with her over the years and look forward to again.

However, Cartermatt expressed concern that Jennifer Love Hewitt joining the show this late could throw off the dynamics of the show.

"Obviously, the concern for the first few episodes of 'Criminal Minds' is that introducing the Kate character is going to offset the balance of the show, mostly because you are adding someone to the mix who hasn't been there, and that can oftentimes be very problematic," it said.

The website cited the case of "NCIS" which introduced the Bishop character into 12 seasons.

This is definitely the problem that "NCIS" season 12 ran into when it comes to the Eleanor Bishop character recently. Played by Emily Wickersham, Bishop was supposed to fill the void left behind by Cote de Pablo's Ziva David, but a number of fans think that she doesn't fit in with the team.