The best thing about this clip from Monday night's episode of "Jimmy Kimmel Live": seeing Lena Headey slide into the persona of Cersei Lannister like it's the world's most comfortable sweater.

Despite being out of uniform (and absent her trademark blonde wig), Headey gamely slipped into character in order to trade barbs with Jimmy, as the two sipped wine out of goblets and took turns smugly zinging each other. Jimmy did his best, but let's be real: nobody ever engaged in a diss-off with Queen Cersei who didn't end up needing a whole lot of salve to soothe that burn.

The actress was making her appearance in the wake of the shocking "Game of Thrones" season four finale, which, despite certain instagrammy insinuations otherwise, did not include the introduction of a certain long-awaited character. For those who've been wondering, Headey reportedly pled ignorance about that whole thing, saying that she posted a pic of an *ahem* stone heart just because she thought it was pretty.

Do we believe her? It's a tough call. On one hand, Lena has readily admitted to not reading the "A Song of Ice and Fire" series upon which "Game of Thrones" is based, which means that she certainly could have posted that pic without realizing its potential significance. On the other hand, though... well, just look at the shirt she was wearing, and then tell us if we're not all being trolled.