(S02E06) Sometimes having guest stars on your sitcom is a boon; seeing well-known actors or other celebrities mix with the established cast is great to watch and makes the episode memorable. But a lot of other times, bringing in a guest star dampens the chemistry of that established cast and slows down the comedic flow of the show, almost bringing it to screeching halt.

This week's HIMYM episode has two guest stars: Bryan Cranston as Ted's touchy boss, and Jane Seymour as Marshall's testy law professor. And, in this case, one guest star gave us a good result and the other gave us a bad one. I'll tell you who's who after the jump. You might be surprised at who I thought was the chemistry killer.

OK, I'm not going to keep you in suspense. I really like Bryan Cranston -- he was great on Malcolm in the Middle, and who can forget his Seinfeld appearances as Tim Whatley -- but he was kind of wasted here as Mr. Druthers, Ted's mean boss.

Yes, he's supposed to be playing a tense, half-looney architectural genius who just can't see that the building he designed for a Spokane bank looks like a big ol' willie. And Lilly using her kindergarten teaching skills to show him a lesson -- she steals his "Pete Rose Pete Rose Pete Rose" ball because he was mean -- was pretty funny. And I like seeing a little more of Ted's job, which we saw none of last year. But the beauty of the show is the interaction of its five main characters, and for some reason, throwing a standard mean boss character in the mix disrupted that delicate balance.

However, it did give us a chance to a) find out how Ted got to design that building in Spokane, b) gave us a chance to see Charles Robinson (Mac from Night Court), even if he just came on to say, "This is a penis!", and c) helped coin the phrase "justice khakis."

Craig and Carter keep finding ways to keep Lilly in the mix. And now we see that she and Marshall can hang out and not get all emotional. Heck, he even took a Polaroid of her when they saw her as a waitress at that luau restaurant.

Seymour worked a lot better, mainly because she was there to finally challenge Barney emotionally. Heh, did I say emotionally? I meant sexually... he tries to seduce her so she can ease up on Marshall's class and just can't keep up with her. She grades him, giving him a C-minus the first time, professorily chiding him how unprepared he was. But he keeps trying, bless his heart -- I liked seeing him chug a six-pack of Red Bull as he goes to her apartment for the third time. When she finally gives him (and Marshall) a B-plus, it's at the cost of a dislocated hip. On Barney.

But the Best Barneyism this week is not his definition of "a cougar," which is a term I've heard before for an older sexy woman who's on the prowl. No, it's how he stalks the professor at the beginning of the episode, peering through the fern in the hall like it's a jungle thicket, giving Marshall the characteristics of the cougar as if he was on a nature show: The hair, the blouse, the claws...

Finally, we have the final collection of "building related" jokes this week:
- Ted's boss is just being testy.
- He's just being a bit crotchety.
- Don't be so hard on him.
- Don't blow it.
- The building rising out of the brunette trees.
- The building is so bold it'll slap you in the face.

Not bad for an 8:00 show, huh?

Anyway, not the best HIMYM episode of the year, but it had its moments. Let's hope the next set of guest stars do a little better.