Episode #321 "Dick and the Other Guy"

Dr. Liam Neesam, the new professor, is causing quite a stir on campus; Dick thinks he's a hot shot but can't help being fascinated, because Neesam's a lot like him, pompous and completely self-absorbed. Sally suddenly finds herself dateless and decides that she and Don should get back together, but Don is mysteriously unavailable, and women at Globey's Bar and Grille have all begun gushing over him; Sally's really baffled when she hears one of the women refer to Don as Donnie Orvellini. Neesam proves his superiority to Dick in the classroom, on the golf course, in the kitchen and in the pub at darts, but when he seduces Mary it's the last straw, and Dick finally figures out Neesam's true identity. Sally learns that Don has become Rutherford's king of karaoke; she's intimidated, but confronts Don who tells her that music is his life now. Sally says she wants to be part of that life, and they sing a duet. And Dick confronts Neesam and says he knows he's an alien. Dick is about to reveal that he too is an extraterrestrial until Neesam says he'd planned to destroy the planet until he met Dick who seemed intelligent enough to justify saving it. Neesam uses a device on Dick to make him forget their conversation; it's supposed to melt about half the human brain, but Dick is safe since he isn't human.