The episode synopsis for 2×04 “Quill” reveals trouble for our favorite Wesen creatures!

“Quill” will air September 3 at 10 p.m. on NBC

Episode synopsis:

A MYSTERIOUS OUTBREAK HITS TOO CLOSE TO HOME FOR MONROE AND ROSALEE – While investigating an accident site, Nick (David Giuntoli) comes upon a bizarre and gruesome Wesen disease that is spreading quickly. A romantic day out for Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner) takes a dangerous turn when they encounter an infected creature that is out for blood. Meanwhile, Captain Renard (Sasha Roiz) gets a tip about a dangerous foreign fugitive who’s made his way to Portland.