They've released the full synopsis for that week's shows, including Arrow and The Flash, and it seems we'll get our first look at the Reverse Flash that week -- while Eddie Thawne...well, there's no way around it: it seems like he's planning to propose to Iris.
Of course, teaser text can be designed to tease. Don't set your clock by a prediction we make after reading one paragraph.
Dr. Tina McGee, played by Amanda Pays reprising her role from the '90s version of the show, also joins in the action.
...And Firestorm shows up. So...big reunion for the midseason finale/holiday episode.
You can see the final synopsis below.
"The Man in the Yellow Suit" — (8:00-9:01:30 p.m. ET) (TV-14, V) (HDTV)
BARRY COMES FACE-TO-FACE WITH THE MAN IN THE YELLOW SUIT/AMANDA PAYS RETURNS TO THE FLASH — Barry (Grant Gustin) finds himself face-to-face with his nemesis, the man in the yellow suit, a.k.a. Reverse Flash, who killed his mother. Barry is frustrated when the Reverse Flash escapes, but Dr. Wells (Tom Cavanagh) and Cisco (Carlos Valdes) come up with a plan to trap him. All they need is bait, so they turn to Dr. Tina McGee (guest star Amanda Pays) from Mercury Labs to help. Meanwhile, it's Christmas at The West household and Iris (Candice Patton) is in full holiday cheer. Eddie (Rick Cosnett) gives her a surprising gift but also leaves her with a question that could change her life. Joe (Jesse L. Martin) joins the search for the man in yellow and ends up in the crossfire. Caitlin (Danielle Panabaker) finds Ronnie (Robbie Amell). Ralph Hemecker directed the episode written by Todd Helbing & Aaron Helbing (#109). Original airdate 12/9/2014.