This week's Grey's Anatomy solved some mysteries (i.e. who is Dr. Fields’ love interest going to be?), but also created some new issues (i.e. what is going on with Lexie and Avery?).

Throughout "P.Y.T. (Pretty Young Thing)," Meredith demonstrated her ability to relate to Alzheimer’s patients and their families. The Chief decided, however, that he wanted to start a clinical trial to cure diabetes based on research he found in one of her’s mom’s journals.

Richard explained that he would not complete the trial without Meredith, and she ultimately had to choose between Alzheimer’s and diabetes research.

Meredith gave the Chief permission to go through with the diabetes trial alone after she decided curing Alzheimer’s was more important to her than continuing her mother’s work.

This plot line emphasized that Meredith really never knew the same woman that the Chief did and is most concerned with keeping others from suffering from the same pain that she faced growing up with a sick mother. 

Mark and Arizona ganged up and tried to keep Callie healthy for the baby. Callie could not resist caffeine and eventually rebelled against Mark and Arizona. The episode ended with the three of them actually getting along in the apartment. 

Do you think that Callie, Arizona, and Mark can maintain this positive dynamic? 

Callie, Owen, and April operated on a patient who tried to be a human slingshot in an attempt to find Internet fame. The patient figured out the error of his ways when Owen told a story about a soldier who was injured trying to save others in combat.

Owen did not have a very large role in this episode, but this was a strong scene. Will he fade into the background or will a new story line thrust him back into the spotlight? 

Thatcher Grey was admitted to the hospital, surprising Lexie and Meredith. Lexie found about his new girlfriend when the girlfriend arrived at the hospital kissed him.

Lexie was upset that the girl was her age and acted cruelly toward her. After Meredith told Lexie to let their dad be happy, Lexie and the girlfriend found common ground in caring for Thatcher. Lexie has had her share of problems lately. Hopefully, things will start looking up for her.

In other Lexie news, Mark bribed Avery with surgeries to get him to spy on Lexie and find out why she was so upset. Avery successfully got Lexie to spill her guts in exchange for candy. 

She admitted to being upset that Mark is having a baby and leaving her behind without consulting her. She also said that she missed Mark but that the relationship had to end since Mark had messed up for the second time.

Avery told Mark that he could not get any information from Lexie, but Mark still let him scrub in. Avery seemed to have a real connection with Lexie. At the end of the episode, Avery asked Lexie out informally, and she said yes.

Avery and Mark clearly both want to be with Lexie. If Avery had told Mark what Lexie had said to him, do you think that Mark could have fixed things with her? Did it make you like Mark any less that he abused his power to get Avery to spy on Lexie? 

Mark clearly will not be happy if he finds out that Avery and Lexie are spending time together. Who do you think Lexie is going to end up with?

Finally, Alex and Dr. Fields got off to a rocky start when he used offensive language to describe a baby that was a candidate for organ donation.

Dr. Fields had Alex removed from the transplant case and made Alex feel insensitive for not thinking about the mother who birthed the injured baby.

Dr. Fields later saw another side of Alex when he insisted on staying with the recovering baby in the NICU. Alex and Dr. Fields ended up in an elevator, and she refused to go out with him. It seems like the writers are setting up a future relationship.

Do you think they have good chemistry? Did you like the episode overall? Browse some of the night's best Grey's Anatomy quotes and comment below!

Lexie: You're not his family! You're his midlife crisis! | permalink

Mark: Peanut butter cups. She's a stress eater. You get her eating, you get her talking. She loves peanut butter cups. | permalink

Alex: I thought I knew all of the nurses on this floor. How did I miss you? | permalink

Mark: That goo looks great. I say stick with the goo. | permalink

Meredith: One of the hardest lessons as a doctor is learning to prioritize. We're trained to do all we can to save life and limb, but, if cutting off a limb, means saving a life, we learn to do it without hesitation. It's not an easy lesson to learn, and it always comes down to one question, "what are the stakes?" What do we stand to gain or lose? At the end of the day, we're just gamblers trying not to bet the farm. | permalink

Cristina: If you continue to whine about how you can't decide which groundbreaking medical advancement to put your name on, I'll punch you in the ear. | permalink

Cristina: It's Sophie's choice.
Meredith: It's Sophie's choice?
Lexie: I've never seen that movie.
Cristina: Well, you should. It's really funny. | permalink

Callie: Kepner, I need you to speak differently.
April: I'm sorry.
Callie: It's your voice. It's a little um—just speak differently.
April: Like with an accent? | permalink

Cristina: There's no way she's twenty. She's gotta be like 26, 27.
Lexie: I'm 27.
Cristina: Oh. Gross. | permalink

Teddy: For someone who has a history of ambivalence towards motherhood, you got the whole guilt thing down cold. | permalink

Cristina: You're the one who needs to keep his mouth shut, cabbage patch. | permalink

Lexie: That's what happens when your boyfriend's an old man. Old men get cancer. | permalink

Lexie: I never really got it before, but this is how he operates. He starts up new families, stops talking to the old ones. He'll go off marry Dani the tattooed lady, have six little mid-life crisis babies, and I'll never hear from him again. It's exactly what he did to you. | permalink

Chief: She didn't give you a lot of love, but she gave you her talent and her name and this. | permalink

Lexie: Crap, my dad's tatted up skank isn't the bitch. I am. | permalink

Meredith: I think it's right that you continue her work, but I just really want to cure her disease. | permalink

Meredith: Surgery is a high stakes game. But no matter how high the stakes, sooner or later, you're just going to have to go with your gut, and, maybe just maybe, that'll take you right where you were meant to be in the first place. | permalink

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.