Monroe and Rosalee's big day will finally arrive in the season finale of "Grimm" this Friday, however, their wedding will be overshadowed by unforeseen events.

A promo for the Season 3 finale, entitled "Blond Ambition," shows a clip of Monroe and Rosalee at the altar. Although they are overjoyed about getting hitched, their celebration will take a backseat to the heartache for those around them. In addition, Nick and Juliette will come to a shocking realization that causes tension in their relationship. Meanwhile, Trubel will become really violent once again.

In an interview with TV Guide, actor Silas Weir Mitchell teased what's to come in the finale. "All hell breaks loose... there are no zombies, but lives change," Mitchell said. His co-star Bree Turner added that "This is the biggest episode we've shot. It's so major what we're trying to accomplish... and things [happen] that absolutely trump this wedding day."

Co-creator David Greenwalt also hinted at what's to come in the May 16 season finale. "We have doozies of cliffhangers that should be even more exciting than previous years," said Greenwalt. Because Monroe and Rosalee's wedding will attract a guest list full of Wesen, Nick will try to disguise the fact that he is a Grimm by wearing sunglasses, which may or may not work. Someone is also "gonna get hurt" in the episode, Greenwalt added, reports TVLine.

According to Dread Central, the synopsis states: "It's Monroe (Silas Weir Mitchell) and Rosalee's (Bree Turner) big day, and their joy will only be matched by unexpected heartache for those around them.

"Nick (David Giuntoli) and Juliette (Bitsie Tulloch) make a startling realization that could shake their relationship to its core.

"Meanwhile, Adalind (Claire Coffee) proceeds with a delicately laid plan that leads to a catastrophic event that will alter the course of Nick's journey. Russell Hornsby, Sasha Roiz, and Reggie Lee also star. Jacqueline Toboni, C. Thomas Howell, Dee Wallace, and Chris Mulkey guest star."

"Grimm" Episode 3.22 "Blond Ambition" airs on NBC on Thursday, May 16, 2014 at 9 p.m. EDT.

Watch a preview below.