In this photo from the fourth season finale of Grey's Anatomy, "Freedom," Callie and Mark share a moment outside the hospital. What's to come of these two?

In this photo from the fourth season finale of Grey's Anatomy, "Freedom," Callie and Mark have a conversation outside Seattle Grace. What's to come of them?

In this photo from the fourth season finale of Grey's Anatomy, "Freedom," Callie and Mark have a conversation outside Seattle Grace. What's to come of their relationship, if anything?

In this photo from the fourth season finale of Grey's Anatomy, "Freedom," Callie and Mark have a conversation outside Seattle Grace. Will they get together?

In this photo from the fourth season finale of Grey's Anatomy, "Freedom," Callie has to be happy about something... but what?

Callie and Erica talk in this photo from the fourth season finale of Grey's Anatomy, "Freedom."

In this photo from "Freedom," the 4th season Grey's Anatomy finale, Cristina watches Callie and Erica operate. Yang comes into her own later on.

In this photo from "Freedom," the 4th season Grey's Anatomy finale, Callie and Erica share a near flirtatious moment during surgery ... later they succumb to their desires. Hot!

In this photo from "Freedom," the 4th season Grey's Anatomy finale, an intense Callie Torres shares a look with Mark during surgery. But her mind is on another doctor ...

Callie Torres and Erica Hahn operate at Seattle Grace. Erica (Brooke Smith) and Callie (Sara Ramirez) are the latest buzzed-about Grey's Anatomy Couple

Callie and Erica are the talk of Grey's Anatomy after their hot, Season Four finale kissing. What's to come of them in Season Five?

Following a place crash and a shoot out, Heroes unite. Will Peter, Ando, Hiro, Mohinder and Parkman get their revenge?