A big crisis is going to greet Frank Reagan (Tom Selleck) when "Blue Bloods" returns for season 6 today, and his daughter seems to aggravate the situation.

An exclusive preview for the season premiere titled "Worse Case Scenario," shared by ET Online, shows the NYPD Police Commissioner arguing with his daughter Erin (Bridget Moynahan). As an Assistant District Attorney, Erin is tasked to make her father reconsider his plan of handling the imminent terrorism threat against the city. But based on the preview, Erin has a hard time explaining her case to her dad. 

"What if you raid that apartment, kill three Muslims and don't find a single bomb on-site? That's a lot of backfire that you're standing in front of," Erin contends.

However, Frank is already determined to execute his plan. He ends their discussion by showing her the door while saying, "I'll take that risk." 

The said threat is teased in the official synopsis of the episode, which reads: "Frank goes on high alert when a threat to New York City may be imminent following a terrorist attack in the Middle East." 

Another preview shared by TVLine shows Frank with his group of detectives working on the case. Frank tells his team to be alert and prepare for all types of situations that could possibly happen and keep the chopper ready. 

Detective Abigail Baker (Abigail Hawk) enters the room to drop several bad news. Apparently, there has been a couple of subway bombings in London, while a market in Bangladesh has been attacked as well. Frank believes that if these events around the world are happening, a similar assault could happen in New York City.

"Blue Bloods" season 6 premieres 9 p.m. Central Time on Friday, Sept. 25, on CBS. Fans of the series can also catch the show online for free for an entire month if they sign up with the live streaming services offered by CBS.com.