Martha and Clark are brought down by contaminated spores in the fruit cellar, and Clark, who loses some of his power, must find a cure. Disease Control troops find the spaceship key Martha hid, forcing Jonathan to activate the spaceship for her rescue.
Martha hides the spaceship key she retrieved in an earlier episode, by hiding it in the fruit cellar near the spaceship, but she inhales meteor-affected spores and collapses. Jonathan and Clark get her to the hospital, and the Disease Control Agency gets involved after being notified of the case by Dr. Bryce (Emmanuele Vaugier, in her third Smallville appearance), who reveals that Martha is pregnant. The DCA searches the Kent farm, forcing Clark and Pete to move the spaceship, but Clark became infected, loses some powers, and control of the Dodge pickup. In a bit of clever camera work, he and Pete appear to push the truck back onto the road.
So far so good, until the storyline stretches too far with camo-geared troops guarding the DCA cache of contaminated material and helicopters and Humvees instantly ready to pursue any intruders, like the bull-in-a-china-shop Jonathan. His break-in to get back the spaceship key, easily found in a plastic baggie (which wouldn't protect anyone from a real contamination threat) ends in a clever escape ruse. The chase has the unbelievably efficient military-sheriff intercept thwarted by Pete who is actually driving the Kent's truck. The activated spaceship provides a "miracle" cure for Martha, then we have a nice tension build-up when Dr. Bryce gets a blood sample from Clark while in his weakened state. She discovers it's radical differences, and tries to hide the analysis from Lex, who offers her the key to his mansion, and a bribe to a hospital tech to get the blood report.
As Clark recovers at home, Chloe visits in her red New Beetle cabriolet, and, in a touching scene, quietly reads a love letter to him while he lies sleeping. The FX folks create an impossible celestial event - a rising crescent moon pointing upward - toward a sun which has already set - time for an astronomical advisor. Ms. O'Toole and Ms. Mack do the best acting here, for a re-run rating of B-.