We may as well get this out of the way right at the start – this episode of Supergirl isn't the true beginning of the big cross-over event that we have been promised. More than likely, it was never truly intended to be. What it actually is, more than anything, is a concerted effort to bring the conflict that has carried us through the season, so far, to a satisfying close – perhaps, in preparation for Supergirl's impending trip to another universe.
It probably shouldn't have been necessary to open with that – but, then, it seems as though all of the advertising for the big cross-over is presenting it as something set to take place over four nights, so that's bound to have led to some disappointment.
So, instead of any direct links to the Dominator's impending invasion, this episode concerns itself, primarily, with Cadmus's latest efforts to wipe out aliens on Earth – efforts which, in this case, centre around the use of a Kryptonian bio-weapon recovered from Superman's Fortress of Solitude. This was, after all, the entire purpose behind Lillian Luthor's efforts to steal Supergirl's blood, in the previous episode.
It all adds up to an entertaining episode, overall – even if the action does feel a little more restrained than what we saw in the previous episode. There was room for one fun, if brief, confrontation between the Martian Manhunter and Cyborg Superman – something which seemed to be almost a requirement given the history between the two characters (with the fact that they are both played by David Harewood also adding another extra layer of complexity to the whole matter). But, beyond that, this felt like a much slower paced episode than the previous one – which feels a bit strange, given the drastically heightened stakes.
Of course, what this episode might lack in action, it more than makes up for in character drama. Family is clearly an important theme of this episode – and, with both Lena Luthor and Kara forced to confront the various sins of their own respective families, there is obviously plenty of potential drama to draw on. For Lena, obviously, there is her status as an adopted member of the Luthor family – with a brother who happens to be one of the world's most well-known super-villains, and a mother who seems set on heading in the same direction. The small matter of whether or not Lena Luthor could actually be trusted has been a recurring issues for much of the season so far, of course – so, having that particular issue be brought into the foreground here, as Lena learns of her adopted mother's plans, adds an interesting complication to the episode's central conflict.
For Kara, meanwhile, the episode also features the surprising, though very interesting, revelation that it was actually her father who was responsible for the creation of the Medusa virus – originally planning for the bio-weapon to act as a defence against any potential invasion of Krypton. Kara has already been given plenty of reason to realise that her parents were far from perfect, of course – so, adding this on top is more than enough to leave her confidence momentarily shaken.
Of course, there are some minor questions raised by this whole central plot-line which don't seem to receive any sort of satisfying answers. How and, more importantly, why was this alien bio-weapon sent to Earth, in the first place? Why was it kept in the Fortress of Solitude? How did Lillian Luthor and Hank Henshaw even learn about it? And, probably least important, why was it named after a figure from Earth mythology? None of these questions are very important, I suppose – but, they still bothered me, a little, throughout the episode.
With regard to this season's romantic sub-plots, the episode also found some time to move things forward. I do have to admit, though, that the screen-time spent exploring Kara and Mon-el's possible feelings for each other actually proved to be a source of genuine frustration for me – not because I have any particular issue with the relationship itself, of course, but simply due to the irritatingly melodramatic manner in which it all played out. Rather than simple directly addressing the possibility that they might be attracted to each other, we were forced to watch while they, instead, spent much of the episode tip-toeing around the whole issue while casting meaningful glances in each others direction. It was annoying. Alex and Maggie, at least, continue to inch their way forward in a much more reasonable manner – as, Alex continues to come to terms with her own sexuality, by coming out to her mother, while a near-death experience at the hands of a homicidal cyborg is enough to convince Maggie that it might be worth seeing where things might lead with Alex, after all.
Possibly the strangest aspect of this episode is in seeing exactly how neatly everything is wrapped up by the end. With Lena revealing that she is firmly on the side of 'good', after all (or, at least, that she is firmly set against her adopted mother), Lillian's carefully crafted plans actually seem to fall apart rather easily, by the end. That's not nearly as strange as the very off-hand manner in which Mon-el's illness, and even J'onn's gradual transformation, are essentially cured off-camera by Dr Eliza Danvers (Helen Slater) – who has paid a visit for Thanksgiving.
The relative ease of Lillian's defeat was a bit strange, but I'm prepared to give it a pass – if only because it provide scene for Lena Luthor. But, the off-hand manner in which Dr Danvers is able to 'science' away everyone's problems, essentially during a commercial break, came across as a very unsubtle attempt to 'wipe the slate clean' – and, it didn't work for me, at all. Also, the episode manages to come to an end without actually addressing the fact that M'gann M'orzz is still being held in the cell that J'onn tossed her into – which is another thing that genuinely bothers me.
Those feel like somewhat minor issues, though (and, in the case of M'gann, at least, it is something that is certain to be addressed when the series returns, early next year) – and, none of them do much to undermine what is, overall, a genuinely great episode of Supergirl. With all of the current conflicts so neatly resolved, it also means that Kara is in the perfect position to head off with Barry and Cisco, when they come to recruit her at the end of the episode – so, there's that, too.