Doctor Spencer Reid (Matthew Gray Gubler), the genius doctor and the youngest profiler in Behavioral Analysis Unit (BAU) in "Criminal Minds" is reported to have a huge episode in season 12. This is because his mother Diana Reid (Jane Lynch) is returning to the show since her last appearance in 2008.

"Criminal Minds" season 12 episode 11 ‘Surface Tension' is said to be a significant episode for Reid, which is going to be emotional, according to a report. In the middle of the case that the BAU profilers are trying to solve, Reid would still do the best that he can to figure out a future for him and his mother who is suffering from Alzheimer's disease.

It is also worthy to note that episode ‘Surface Tension' will not be the end of Reid's story in "Criminal Minds" as he will have another episode titled after his name ‘Spencer' in the coming weeks. As AJ Cook (JJ) said in an interview with TV Line, all the drama that have happened in the past year opened a door for them to write a storyline that is more captivating yet nerve-racking particularly on Reid's story.

"We've got some very personal stuff happening to some very loved characters, so there will be mayhem within the fandom," she told TV Line. "But don't worry, stick with us." Jane Lynch, on the other hand, will also appear in one more episode before the season finale and there will be more great performances to boot as well.

Another interesting report is that the second half of "Criminal Minds" season 12 would be more serialized than any other episodes to date and this is said to be based on a single character in the BAU. Meanwhile, the case in the ‘Surface Tension' episode involves strange hieroglyphs found in a dead man's armpit that traces back to other bodies from the past.

If this is a new serial killer on the loose again, fans should know soon! Stay tuned.