This was a great episode for Kate and Leonard and for who, like me, ships them as a romantic couple.
They had two (and a half) scene together, and both of them contained references to their feelings towards each other, especially Leonard's, because, as always, he's expresses his feelings more easley than Kate.
In the first scene, we have Leonard realizing how his new jobs sucks, and what does he do? He calls Kate. Yes people, Leonard Knox's mind reacted to this sad feeling deciding to call Kate.
Since the very first few words we can see the brilliant sarcasm we used to love about their dialogues in season 1. I absolutely loved that "Is there anything you'd rather hear?"
It takes a while, but he gets to the point: "I miss you". Kate reacts to this confession with a "Leonard..." that sounds a lot like "please, don't do it", which makes clear that she's still running from her feelings for him, so she doesn't wanna hear his, because it's not helpful.
Then she gives him a very motivational speech, showing for the first time that she believes in him.
Also, that "You chose Texas" feels a lot like a "You chose Texas instead of me", like she managed to let him go with a very long and sad process, but it still hurts.
She quits the conversation really quickly, pretending to have things to do, running away from her feelings as always.
In the next scene they have together, Leonard is back in NYC.
Kate is shocked. She doesn't have the positive reaction Leonard was probably hoping for, and we can't blame her: he stole her case, and this is not the kind of things that happen to Kate Littlejohn.
Leonard basically says he came back for her, and after a short moment of disorientation, she denies (as always) to be happy about that, saying he made a mistake, and leaving him kinda hurt.
We can see how hurt he is when, after winning his case, he passes by her office, sees her, stops for a moment, and then keeps walking, looking away.
It's easy to see a parallel with episode 1x01, when he had just won his case against Sandra but, for some reason, he was kinda sad: he saw Kate working in her office and, contrary to this time, he joined her.
Not the welcome back you were expecting, uh, Mr Knox? Looks like you're gonna have to work a little to make her crush her walls.