'Doctor Who:' The ballad of Amy and Rory

After a scary episode like last week's "Night Terrors," most shows would take the week off and throw on a fun filler episode.

Not "Doctor Who."

"The Girl Who Waited" was the most emotionally charged episode of "Doctor Who" since "The Impossible Astronaut."

Amy, Rory and The Doctor are travelling to the second most popular planet among discerning space travelers (because everyone goes to the first) when Amy is separated and trapped in a quarantine facility that uses multiple time streams.

The Doctor tells Amy to wait, then sends Rory to rescue her. Unfortunately he gets the time streams mixed up and Rory discovers a Amy who waited 36 years for them to come back.

This Amy is jaded and bitter that they left her, and doesn't want to have anything to do with The Doctor.

However, when push comes to shove, she still loves Rory and wants to be with him.

This hour was all about Am and Rory's love affair and how it can span all of time and space. It is thoughts of Rory that help young Amy convince old Amy to help. And when the time streams must be merged, it's their first kiss (during the "Macarena") that's the most powerful thought in the universe.

Arthur Darvill and Karen Gillan gave magnificent performances in this episode, solidifying themselves as two of The Doctor's best companions ever.

Rory has completely come into his own as a hero, saving the day and making the hard choice to leave old Amy behind to save young Amy. He even yelled at The Doctor for how old Amy turned out. Darvill has given Rory real depth, while holding onto the everyman charm that makes Rory so likable.

Meanwhile, Gillan was spot on in her portrayal of Amy's need to survive, while also letting viewers in on the heartbreak behind the bitterness. Amy becoming a kickass action hero is no surprise, but her hating The Doctor, that was shocking.

Gillan expertly had Amy go from scrappy companion to bitter cynic to a woman resigned to her fate. It was her best performance since she began on the show.

As good as the first half of season six was, "Doctor Who" has really been clicking on all cylinders in the second half. It's at a point now, where every week is better than the previous one, which is a real treat for fans.