Sometimes, the writers get tired of writing Clark as a boring block of pasteurized cheese and break out the red Kryptonite. This is one of those times. Here's the short version of how it went down: Tess is "upgrading" John Corben's Kryptonite-powered heart with some primo red stuff so that he can act as her bodyguard. All the while, Zod's still been pretending to be the Blur and asking Lois to investigate Tess. This leads her to the upgrading lab where things naturally go awry because Lois is a clod, but John saves her because he's not quite as crazy as he was the last time he showed up. She returns the favor by trying to get him to safety. Clark, acting like an insecure, hypocritical douche because Lois won't tell him everything that's going on in her life, traces her whereabouts to the lab, where he accidentally inhales some red K dust. His inhibitions lowered, he knocks around Chloe for keeping a stash of Kryptonite weapons and then joins Zod for some super-powered sightseeing in Seattle. What? It was close to Vancouver! They top it off with a trip to the Fortress of Solitude, where they make googly eyes at each other for a while.
Tess's minions manage to get John back to the secret lab, where Chloe is also nosing around. Lois noses around, too, but Chloe sneakily knocks her out with chloroform to keep her in the dark. Tess and Chloe, in a grudging alliance, send John to the Fortress to save Clark once they figure out that he's totally baked. He succeeds (even though both Clark and Zod blow really, really hard on him) because his Kryptonite-powered heart weakens them. He also stabs Clark with some Kryptonite to neutralize the red stuff, and Clark's all, "Aw, poop, now I have to apologize for being a jackass!" He sets things right with Chloe, but his bromance with Zod is short-lived when Tess reveals that Clark has been sneaking around, helping the Kandorian soldiers. This leads to Zod deciding to share his blood, and this his powers, with his soldiers, who look sort of grossed out by the prospect. John, for his part, makes a romantic bid for Lois, but she's sticking with Clark, and gives him the upgraded red heart as a goodbye present.
In summary: I really miss the relatively straight-forward plots we've had for the two weeks.
While you are waiting for Tippi's recap of this confusing episode, browse our guide to the heroes and villains on this show.