Nick (David Giuntoli) tells Hank (Russell Hornsby) that he is unsure about attending Monroe's (Silas Weir Mitchell) wedding as the Wesen could recognize him as a Grimm and decides to tell him that he can't go because of the risk of getting exposed.
Nick visits Monroe and Rosalee (Bree Turner) to tell them that he can't attend the wedding because of the risk of exposure.
Back in Vienna, Viktor (Alexis Denisof) is upset about Adalind's escape and has his associate Gregor (Gene Freedman) killed for his failure.
He then has Marcus Rispoli (Philip Anthony-Rodriguez) named the new leader of the Verrat and they both deduce that Adalind must have returned to Portland.
There's some information from the past the audience didn't know, a tidbit about Wesen/Grimm interaction that fills in a gap that never seemed like a giant mystery, but mostly this is just an episode that gets all the pieces back to the one location they need to be in to bounce off each other.
"[5] MaryAnn Sleasman from TV.com, wrote, "The two concurrent stories running through this episode are where the hour got its name: 'Synchronicity' is the apparent relationship between two or more events that otherwise have no connection.
Monrosalee's nuptial arrangements comes off as quaint and cute, a domestic break in all the running and hiding and slaughtering of Royals, but when you look at it in the context of the rest of this season, their wedding-planning woes are just as high-stakes as Grimm's more intense storylines.