Catherine Avery is back this week so that she can do a surgery with Bailey and Richard and then attend a fancy benefit dinner, while also doing a little bit of motherly meddling in Jackson's life. She brings along her "star urology fellow," Mara, who happens to be young and stunning, and then orders Jackson to take Mara on a tour of the hospital. For some reason it takes him a while to realize that this is a setup, and he tries to tell Mara that he's not interested. She's completely offended that he thought she was, but admits that she is there because Catherine told her to spy on him and find out as much as she could about what is going on in his life. They wind up bonding over lunch and he gives her some tips on how to best handle his mom as a boss. They both get all dressed up to go to the benefit but since Catherine has scored herself a date in Richard (well, for a moment at least) they declare that they are not going. Instead, Mara decides that Jackson's not so bad after all, and they have a hot night in the on-call room. Mark will be thrilled.

Bailey notices that Catherine seems to have her sights set on Richard as she flirts up a storm with him throughout the day. She invites him to be her date to the benefit and he accepts, even going so far to put on his tux. But once he sees her he tells her that he can't go after all. She assures him that she just enjoys flirting and that Adele has nothing to worry about, but Richard explains about Adele's Alzheimer's and how, with his wife not even knowing who he is, he actually really enjoyed the flirting and felt like a man for the first time in forever. He doesn't trust himself to go out with her, so he politely declines, and she seems to understand even if she is now left attending the thing all alone when five minutes earlier she was part of a party of four. My guess is that when you are an Avery, you have no shortage of people to talk to at one of these things.

Alex and Morgan are spending basically all of their time together between his being Tommy's doctor and Morgan still helping him study for his Boards. As we all saw coming from the beginning, she's developed an obvious crush, and he seems to be enjoying her company while getting a little bit emotionally invested in Tommy's recovery. Callie notices what's going on and warns Alex to be very careful, but he scoffs at the very idea that Morgan is interested. However, once the seed is planted, he starts to see that Callie is right. It's unclear if he's going to heed everyone's warnings to shut it down, though.

Meredith and Derek are in such a state of wedded bliss that he gets the bright idea that she should come back to neuro with him. Proving that she really has grown up, Meredith tells him it is an absolutely horrible idea but he is all for it and moves her on to his service for the day, along with Lexie. Their patient has a cyst that needs draining, and while they also found she has a small tumor Derek explains that it is benign and so they are going to just leave it there for now. He gets called out of surgery to go take care of some other emergency and leaves with instructions to Mere to just observe and let Lexie do the whole procedure. As they work on the cyst, they stumble upon the tumor and wonder if they should just go ahead and take it out. Mere is adamant that they wait for Derek and find out what he thinks, but when he gets called into another emergency surgery the girls make an executive decision. Mere comes in to see him later and happily tells him they took out the tumor too, and he blows up at her. He points out that the girl didn't consent to having the tumor out, and it's in a delicate part of the brain, blah blah bad things. Mere is sure that everything went perfectly but they won't actually know until she wakes up. The girl's parents arrive in time to see her wake up and when she does, it turns out she now has aphasia and can't speak -- oh, and did I mention that it's irreversible? Yeah. Mere tries to take responsibility for it but Derek of course takes it all himself, and the girl's parents declare that they are going to sue. That's what we all need: another lawsuit storyline. Mere tells Lexie what happened and Lexie breaks down, but Mere tells her to suck it up when she goes and sees Derek, warns her how he's going to yell at her and ignore her for days, but that then he will get over it and she'll learn from this. That night at home, Derek basically does just that Mere but while he won't look at her, he will at least still communicate in monosyllables; when she asks if he wants her to leave him alone, he says no. So, progress?

Cristina is making progress too... into full-on jealous insanity. It seems that Owen not coming home has become a regular thing, and she's surer with each night that he's having an affair with Nurse Emily. Her patient is a man who is brain dead and Cristina is supposed to get the paperwork signed by his husband for them to pull the plug. The husband can't let go, though, and tells them to keep everything on. Owen orders Cristina to stay there and convince the guy that it's best to let his husband go; Emily is hovering and pipes up that she thinks she could help since she's been caring for the guy the past few days. Cristina tells her no, but Owen orders her to let Emily help. As they try and convince the husband, Cristina sees a parallel to her own life and how her marriage might already be dead but she just can't admit it and let go. After the husband finally signs the papers, Cristina faces off against Emily and accuses her of sleeping with Owen, but it turns out that Emily is just a flirt with a boyfriend, and she and Owen never hooked up. At home that night Cristina waits up for him and orders him to finally start talking to her. She admits what happened with Emily and how relieved she is that she was wrong... and then Owen admits that while he didn't hook up with Emily, Cristina was right and he did cheat on her with someone else.