Germs, germs, germs: They are everywhere in this episode of Grey’s Anatomy (Season 10, Episode 18: “You Be Illin’”). There’s a nasty virus running rampant all over the hospital, and everyone’s afflicted.

So what went down? Here’s what you need to know:

The illness hits pretty much as soon as the episode starts — a nasty pukey mess of a super contagious virus. Almost everyone in the hospital is, eventually, down for the count… although they aren’t so quick to admit it. Not surprising. What doctor wants to be sick? Unfortunately, Leah’s the first to go, and the rest of the Grey Sloan Memorial staff drops like flies shortly after.

The stakes are pretty high for this sickness. If someone in Cristina’s trial catches the virus, the whole thing gets shut down… and we all know how well Cristina would take that kind of news. Also, when these doctors are sick, they’re a pretty bad mood. Like when Jackson comes down with the virus? He doesn’t even want April in the same room as him, which she doesn’t take too well at first.

We finally meet our bubble boy. His immune system is pretty much non-existent, so when he starts getting sick, he’s immediately put into isolation — which makes both the patient and his parents really upset.

Something big could be in Alex’s future for his career. After Jo calls him out on ignoring his significant med school loan debt, Alex needs to figure out a way to make the payments. When a new peds doctor, Dr. Oliver Lebackes, floats the idea past him that he should pull back from the day-to-day surgeon life at the hospital in favor of joining a private practice, where he'd be creating his own schedule and helping kids in third world countries, Alex is all ears.

Derek’s giving his first conference about his project with the White House… and, unfortunately, falls ill just in time to miss his speech. What happens? Meredith — the only person who knows his project as well as he does — gives the speech for him, with her own twist. Have we mentioned how much we love these two recently? If not, we love these two!

Also awesome: Baby Bailey makes his first appearance in forever. We almost forgot about MerDer’s second child! Oh, and Bailey gives April the best advice about being married she could ask for, and it made us so happy to see them bonding as married women. Aww.