I laughed. The ending was hilarious! "Well, first of all, my name isn't Michael Vaughn" WHAM! That was awesome! I have to admit, I'm sort of curious what Vaughn's secret is, afterall, Irina apparently knows it, and still gave her consent for marriage.
Though I have to admit the plot of the episode was weak ... and zombies? WTF? But Lena Olin was back, and there's just something magical that happens to the show when she's on it. She and Victor Garber have this awesome chemistry, that they could read phonebooks and I'd be watching entranced. So, yeah, substandard plot, but made up for by character interactions.