Despite refusing to give up her secret identity, Kara continues to try to work with the DEO. But when a massacre on a freighter reveals something awful about the past of both the DEO and Colonel Haley, Kara has to make an impossible choice.

This is the best season Supergirl has had so far by some distance and this episode is a highlight. This is gutsy storytelling all the way down, flying in the face of the traditional ‘eternal reset button’ approach to superheroics in multiple ways. For a start there’s the DEO, who are revealed here to have actively weaponized aliens in the past. This is a major change, and a vast political embarrassment given the way aliens are embraced on Kara’s Earth. Then there’s Colonel Hailey, her role in the mission and what she represents. Hailey is a threat far more existential than Citizen Liberty ever was; a woman whose decisions and mindset are intent on driving the DEO back to what it was, not what it is or should be. April Parker Jones has always been good but she’s great this week as a character who is antagonistic and morally compromised but convinced it’s for the right reasons. Another extremist but, like I say, one more grounded, and as a result more dangerous, than Citizen Liberty.

But where the episode really lives is in its final act. Hailey’s relentless search for Supergirl’s identity works. Even after J’onn wipes her memory she’s determined to discover the truth and leaves Kara with no choice but to remove knowledge of who she really is from every DEO agent who knows the truth.

Including her sister.

The heart of this show has always been Chyler Leigh and Melissa Benoist and they’ve never been better than they are here. Leigh’s Alex is the dutiful soldier and loving sister who is quite okay with taking this hit for Kara. Kara, the Kryptonian powerhouse who struggled for years to match the two halves of her life, is bereft. So much so she can’t even stay to watch the procedure. It’s a horrific moment and it ends the episode on massive stakes and a massive change. Supergirl’s still in the fight. But just when she needs people the most, she’s in there alone.

Verdict: Clever, poignant and brave this is another great episode of the best kept secret of the CWVerse. Check it out. 9/10

Alasdair Stuart