I also loved the episode and I think the new one is based on Dan Brown's books. The sense of fun and camaraderie among all the characters is what has always done it for me. We have so many shows now that just get darker and darker as they progress. This one manages to stay entertaining. Now that Kate is back, I'm hoping to see more of Ryan, Esposito, and Laney.
I think I agree that Alexis is looking more mature these days, which as you points out, Bearcata, makes sense.