I’ll say one thing for the Tenth Doctor: he’s a lot better at directing the Tardis to the right time and place. Whereas the Ninth accidentally took Rose twelve months off her point of origin, Ten manages to land Martha just twelve hours later, so nobody realises she’s even been gone. Conveniently, this return just happens to coincide with the grand public unveiling of the anti-aging experiment of Professor Richard Lazarus, for whom Martha’s sister is working. A quick reminder, then: this is one where Mycroft Holmes transforms into the Scorpion King. Thankfully, it’s not as bad as that sounds. Nor as awesome.
There have been plenty of stories like this throughout the show’s history – mankind delving into things it doesn’t understand and releasing a monster or other catastrophe (see Jon Pertwee’s first season for the most of these!). You could argue the show has a fundamental anti-science stance, but I think it’s more that it has a lack of faith in the intentions of mankind. We humans simply can’t be trusted to wield great power. The Lazarus Experiment is the perfect opportunity for the Doctor to lecture about the perils of immortality and ending up alone (he should know!) and, admittedly, he gets some good dialogue with Lazarus – in between the murderous rampages, that is.
Basically, it’s a monster story, and a standard one at that. Usually, these types of stories don’t reveal the creature straight away, or keep it in the shadows, but this episode is only too keen to show it in all its grotesque CGI glory. To the BBC’s credit, the visual effects are reasonably impressive, without too much of that obvious compositing going on. Yes, it still looks fake in a way that better direction could have avoided, but these virtual creatures have come along since the burping bins and rubbery Slitheen of season 1. The violence is mostly implied and not shown, horrific without being bloody (see Torchwood for the opposite) but instant freeze-dried corpses can be just as effective as gore.
There’s no apparent alien influence in this episode at all; this experiment is all the work of a human messing with his genes and accidentally becoming a genetic throwback. The science is implausible to say the least, but I am accustomed to such nonsense in countless Star Trek episodes, so it kind of washes over me. That said, however, there is a reference to Mr. Saxon’s involvement in the project – it’s not too far-fetched to suggest that Saxon’s true identity (more on this later) has been sabotaging Lazarus’s work, perhaps causing results beyond what you’d expect of simple genetics – although the Doctor doesn’t appear to suspect any external influence.
This is also the Doctor’s first chance to “meet the family”, get annoyed (and slapped) by another companion’s interfering mother, and be regarded distrustfully, even though he clearly knows what he’s doing and demonstrably saves people’s lives. There’s just no pleasing some people. Martha is finally upgraded from ‘temporary passenger’ to ‘full-time travelling companion’, as she leaves her dysfunctional family behind for more adventures out in the universe.