The script and the direction of the series has shown us there was something wrong with Tom Keen from the beginning. Good acting by Ryan Eggold - his subtle facial expressions - as well as what he said and did made this nearly apparent. Red has been warning Elizabeth about Tom from the start. Only Elizabeth didn't see this.
Why? It's not as if she's been portrayed as so deeply in love with her husband as to be blind to his secret agent treachery. And she's certainly not stupid. But unless some other reason is revealed - Tom was secretly drugging her? - her acceptance of Tom for so long certainly weakens her character.
We'll see what happens with this couple next week - at this point, only the audience knows the truth, and likely Red, or most of it, anyway.
Which raises another, obvious question: who sent Tom to spy on Elizabeth, to the point of accomplishing this by marrying her? I wouldn't put it past Red to be behind this, with his criticism of Tom to Elizabeth just proffered to make sure she wasn't too much in love with Tom, and certainly not adopting a baby to raise with him.
And this, in turn, focuses the spotlight once again on the biggest question is this series: is Red in fact Elizabeth's father? He sure seems to be - his fatherhood of Elizabeth being more obvious than Tom's deceit - but then why is the series at the same time telling us that Red is something else?
If The Blacklist is nothing else - and the individual episodes including 1.15 are quite good in their own own right - the nature of Red's relationship with Elizabeth makes this series one of the most intriguing hide-in-plain-sight stories I've ever seen.
See also The Blacklist Debuts: Alias Meets Jay Z ... The Blacklist 1.2: Mysteries ... The Blacklist 1.3: Construction Site Heights ... The Blacklist 1.6: Truth and Enigma ... The Blacklist 1.7: Natural Immunity ... The Blacklist 1.8: The Father and the Husband ... The Blacklist 1.9: Field Transfusion ... The Blacklist 1.10: Those Words ... The Blacklist 1.11: Red's Retribution ... The Blacklist 1.12: The DNA Meister ... The Blacklist 1.13: Red Writ Large