Unsurprisingly, given the title, The Girl Who Waited is all about Amy. This is Karen Gillan’s episode and she will cause a few tears to be shed, come Saturday.

The story doesn’t waste any time setting things up. The TARDIS trio arrive on the planet Apalapucia and the gang find themselves in a strange white facility. Before you know it, Amy is separated from the Doctor and Rory and, worse, becomes trapped in a separate time stream – one that is moving quicker than theirs.

But that’s not the only problem, as the Doctor quickly realises that they are actually in a quarantine facility for a disease that could kill him. Therefore, he is forced to stay put in the TARDIS, leaving a spectacle-wearing Rory to find Amy again.

The first thing to note is that this is the ‘Doctor-lite episode,’ however while the Doctor’s absence was noticeable in previous stories like Turn Left, that isn’t really the case here. Matt Smith is present throughout thanks to the aforementioned glasses that allow the Doctor to see and communicate through. They are not unlike Torchwood’s contact lenses.

Saying that, with the Doctor left in the TARDIS for most of the episode, it’s up to Karen Gillan and Arthur Darvill to carry most of the action, and they do a terrific job. Gillan gets to play two versions of herself. One is the Amy we’re all familiar with; the other, an older version that has been left alone for decades, struggling to survive. Seeing an older Amy so bitter and angry with the Doctor is such a contrast, and it really gives Gillan a chance to flex her acting muscles.

However, Darvill also has a chance to shine. Rory ends up meeting both Amy’s, leading to a humorous scene between them, and a heartbreaking one later. This also brings up a dilemma for the Doctor, and you see a colder side to the Time Lord as he forces Rory to make an impossible choice. The episode really stretches the TARDIS trio’s relationship and it will be interesting to see if there is any fallout from the conclusion later on in the series.

Even though this is a character episode first and foremost, there are a couple of action scenes to keep things moving along. In particular, the late battle with a samurai-wielding Amy, is particularly thrilling, as she slices and dices her way through a small army of Handbots.

Like Night Terrors before it, The Girl Who Waited is another standalone episode that has (seemingly) no connection to the ongoing story arc. But that isn’t a bad thing. In fact, this is one of the most refreshing Doctor Who episodes in a while.