Is tonight the night?

The night when Derek and Meredith finally, after four years of love, drama, heartbreak and intimate moments, officially decide they want to spend their lives together?

It would be fitting if this happened in tonight's episode, "Elevator Love Letter."

Grey's Anatomy premiered March 27, 2005. If fans could celebrate a MerDer engagement tomorrow morning - four years to the day their love was born - well, it would be perfect.

Derek has to actually come through, though, and his first couple of attempts at popping the question haven't exactly gone well. Can he pull the trigger tonight?

Check out the spoilers, photos and previews we've posted for a primer of "Elevator Love Letter," which also includes the major story of Izzie becoming a patient at Seattle Grace.

Can her friends band together to save her, or is a tragic season finale ahead?

As always, you can discuss "Elevator Love Letter" before, during and after the episode in our

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