As "Criminal Minds" season 12 heads for the explosive finale tonight, fans will expect to see more action and drama unfold as a son becomes hell-bent on finding his kidnapped mother.

According to the synopsis for the season finale, Derek (Shemar Moore) will be helping his former team, the Behavioral Analysis Unit (BAU), to track down the serial killer and convict named Mr. Scratch. The former supervisory special agent is said to be the one who provides the BAU a lead on the villain, who has long been tormenting Spencer (Matthew Gray Gubler).

In the trailer released for the season 12 finale, Derek is seen being welcomed by his former colleagues. With the lead that he is holding, the team members are hoping that they will finally get to where the elusive Mr. Scratch has been hiding all this time. However, before they can do so, they still have to find Diana's (Jane Lynch) captor, Lindsey (Gia Mantegna).

Last week, Diana, Spencer's mother, was kidnapped and her nurse was found dead in an abandoned apartment owned by the culprit. It was also discovered that Lindsey had been keeping an eye on the mother and son's lives for the past six months. In the trailer for the upcoming episode, Diana is seen in what appears to be the inside of a car trunk. Her captor is also seen in the clip and it looks like she has changed her appearance to avoid getting recognized.

A car explosion at a gas station follows her appearance. Considering she has a smug look on her face, could this mean the car that had burst into flames was the same car Diana was trapped in?

Spencer is also seen interrogating someone, asking the person where his mother is. As to who this person is, fans must tune in tonight to find out.

"Criminal Minds" season 12 finale airs Wednesday, May 10, at 9 p.m. EDT on CBS.