Our biggest Doctor Who fan Lizo reviews the third episode of the third series - Gridlock.
After the first two episodes introducing The Doctor's new companion, this is the story where both the series and Martha really start to come into their own.
For The Doctor it's a return trip to New Earth - on his last visit he defeated evil cat nuns and met the mysterious alien The Face of Boe who promised him that one day he would tell The Doctor a great secret.
Arriving underneath the city years later, things take a turn for the worst when The Doctor and Martha are separated, and they both end up on the sinister Motorway - crammed with vehicles on their way out of the city.
Something definitely seems to be wrong, but the truth is even worse than The Doctor could have imagined.
As a story this is far more than a straight action adventure, although The Doctor does the usual amount of heroic running, jumping and rescuing.
It's really a story that explores people's trust in each other. After all, Martha has gone off with The Doctor knowing next to nothing about him.
The Doctor trusts a cat driver he's never met before to help him find Martha. And the Timelord is ready to be told an important message from The Face of Boe - someone he's only briefly met twice before.
Because this is the episode where the Doctor is told a secret that will overshadow the rest of the series. Four words long, it will send shivers up your spine.
But don't think that this is just a story setting up events in later episodes. It's pretty action packed featuring more than one creature from The Doctor's past.
And if your Dad happens to be one of those Dr Who fans who can name every bit of trivia about the series since it started more than 40 years ago, then there's a moment that will have him jumping up and down on the sofa with delight, while the rest of us look on in complete confusion.
Russell T. Davies has put together a beautiful story about having faith in others, and it's the highlight of the series so far.
As well as few incredibly moving scenes, it's also got some genuinely shocking moments.
But more importantly, it finally sees Martha becoming more of an equal to The Doctor, instead of just allowing herself to be the person who runs about after him.
And that's just what's needed, because they're going to need to be an incredibly strong team to cope with what faces them in the rest of the series.
8 out of 10.