Phoebe believes that the cat that jumped into her guitar case in Central Perk contains the spirit of her adoptive mom. Joey's attempt to sell his entertainment center proves hazardous.
When the bodies of two assassins are delivered to NCIS from overseas, Tony and Ziva go under cover to find the intended targets.
When Dave's amateur band loses its lead singer just before a gig, Tina offers to fill in; Marty quickly regrets letting his needy boss crash at his new place.
Allison becomes preoccupied with preparing for the end of civilization after an earthquake follows an apocalyptic dream; an upperclassman seeks out Ariel for help with geometry, then asks her out.
Denny asks Alan to help him take on the Department of Homeland Security when he learns his name is on the no-fly list; a third-grade teacher is charged with wrongful death after a student has a fatal allergic reaction in class.