A ruptured appendix, the attempted murder of a beloved deacon and a Blackappella (or should we say Quarterblack?) reunion.

From guest stars to plot lines, you know Psych delivered another pitch-perfect episode tonight with "Let's Doo-Wop It Again."

First, we were treated to an abundance of guest stars: Cheech Merin, Mekhi Phifer, Jaleel White and Kristy Swanson each killed it in their respective roles, and I can't be alone when I say that we'd love to see them all again very soon!

Meanwhile... Shawn's appendix bursting? Definitely a semi-shout-out to James' real life struggle with his appendix not too long ago. We can be sure, however, that James didn't have to fight any would-be murders during his ordeal. However, Shawn really got his hero on attacking Jimmy like he did. Looks like he picked up some moves from Mario, formerly of Paths of Love, last week. Where else could he have gotten the shatter-vase-over-head move? Nice move, buddy.

Then there was the re-emerging debate over the group's name: Blackappella or Quarterblack. One is clearly more on point than the other, but Shawn insists Quaterblack is the most correct.  I am still torn on the issue regardless of its mathematical accuracy. Each rolls off the tongue fairly well. Try saying each aloud to yourself. You'll see what I mean.

I would be remiss if I didn't take a moment to mention just how much I love Carlton and Marlowe together. Ever since "This Episode Sucks" I haven't stopped gushing over the chemistry these two have and what a joy it is to watch them be the unconventional couple that they are. Punching your boyfriend has never gone so well! Carlton was uncommonly gracious about the whole thing. You know that he wouldn't have allowed that of anyone else for the sake of a case!

Gus was right to enlist Marlowe in tracking down gang ties related to Deacon Jones' shooting, and it was particularly convenient that his suggestion not only created a more willing ally out of Carlton, but also gave Carlton some face time with his leading lady.

As of this moment I am officially campaigning for Carlowe to become a more permanent feature of season 7. We need Swanson as a series regular, don't we? Get petitioning, Tweeting, facebook-ing, etc., Psych-Os.

The songs from this epsiode was also an understated high point of this hour. The opening sequence featuring the real voices of James, Dule, Jaleel and Mekhi were music to everyone's ears. The same goes for the much missed musical Psych-out. They really should do those more often as opposed to bloopers, though both versions are more than welcome!

Other highlights:

• Juliet's refusal to fluff Shawn's pillows
• Shawn pulling off symptoms of IV overdose. He is hilarious high.
• NO TOUCHING! Enough said.
• Chief Vick making an appearance (however brief).
• BoyzIIMen acappella theme song.

Which do you choose: Quarterblack or Blackappella? Let's settle this once and for all.

C. Charles is a TV Fanatic Staff Writer. Follow her on Twitter.