Au revoir, Diana, you creepy baby, you!
In a truly shocking ending, Grimm Season 3 Episode 18 pulled the wool over our eyes as Captain Renard and the rest of the Nick's team end up ultimately helping Kelly hit the road with Diana.
It's a good decision to bring the baby story to a close. Mostly, as the installment progressed, it became clear that the stalemate between the Royal and the Resistance fighters over the baby and its power would quickly grow boring and tenuous.
As each side fought to one up the other, and as Nick and his (very well formed team) ended up being caught in the middle, Renard made the very admirable and costly choice of handing the baby over to Viktor.