Poor Bub boinked her beak!
I have no idea how this little muscovy duck damaged herself, but the top of her beak looks like it hurts. She’s safe and sound in a private room (in the kitchen) so she can have a bit of peace and quiet to recover.
When she has fully settled down, I’ll give the wound a good rinse and see if there’s anything else to be done. Keeping her clean, warm, and quiet for a couple of days is probably all it will take to have her on the mend.