Last night's Grey's Anatomy was all about three children - a prematurely born baby, a terminal 10-year-old, and a 15-year-old whose drug use landed her in the ER - in dire straits.

Much like last week, there was a seemingly impossible case on the table, and the emotional stakes were high. Unlike Derek Shepherd, however, Arizona Robbins did not save a life.

But because of the way she carried herself, she may have saved countless lives down the road. How? For a full guide, check out our recap of "Invest in Love." Now, some thoughts:

Before touching on Arizona's big storyline, we must touch on Justin Chambers shirtless. You wish, right ladies? Yup, Dr. Alex Karev was forced to lose his shirt to save a baby's life.

Babies thrive on skin-on-skin contact, especially under duress, and as if Alex whispering to a preemie, "you're not alone," wasn't enough to make us swoon ... him shirtless? Wow.

We liked how Bailey mused that Karev would be good in pediatrics. It's almost like we've heard that before. Oh yeah, we have, three seasons ago, when he was working with Addy!

Cristina went rogue last night. It was kind of awesome.

Meanwhile, treating a teen who fell off a roof, Cristina goes rogue in the O.R. and Jackson has her back! She's testing Owen's patience and seems perfectly okay getting reamed out.

After all, she stepped in and performed invasive cardio procedure herself, even though she is technically unqualified and with two attendings screaming for her to stop. Rogue, alright.

Jackson thinks it's hot and later tries to plant a drunken kiss on her. She pulls back, but we're liking the direction this is headed ... a little romantic tension never hurt on this show.

The big star of the episode is Jessica Capshaw's Arizona, who treats 10-year-old Wallace. A proposed operation will only buy him two more months, so Robbins doesn't want to do it.

Until the Chief and a $25 million donation from Wallace's parents persuade her, that is. The surgery goes alright, but complications arise and he dies while Arizona tries to save him.

Arizona didn't save a life last night, but came through just the same.

This is where she really shined. Clearly furious with the huge dollar signs in the Chief's eyes, she told him how it is, and demanded to speak to the parents despite his objections.

She did, and given her obvious compassion, the parents decided to give the hospital $25 million anyway. With that money, she can make a lot of magic happen for years to come.

It was also Arizona's birthday, and she cried at the party Callie threw for her. We have to say, we love them together, and not just because they're lesbians. Because they're people.

They're just a great, believable and enjoyable couple to watch on screen who happens to be 100 percent female. Callie was second fiddle to Arizona last night, which was great, too.

Like last week, when it was Derek's storyline and Meredith just supporting him in bed, there doesn't have to be "couple" drama in every episode to make you appreciate one half.

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