Serge Houde

While explaining Peter's otherworldly origins to Olivia, Walter flashes back to 1985 and the mystery springs forward by revealing the past. Also, Peter's mother (guest star ORLA BRADY) is introduced - and details of the neighboring world reaffirm that there is definitely more than one of everything.

Clark confronts an unexpected foe when a talented art student, Justin Gaines (Adam Brody), returns to school after being hit by a car. The accident robbed Justin of the use of his hands -- but it left him with the gift of telekinesis, and he uses the power for revenge against those he considers responsible for his condition. Meanwhile, after observing Clark with Chloe, Lana becomes jealous and begins to question her relationship with Whitney.

When Clark tries to warn Lana and Chloe about Ian (Jonathan Taylor Thomas - "Home Improvement," "Wild America"), an overachieving student who is surreptitiously dating both girls, they accuse Clark of jealousy. But Lana and Chloe realize too late that Clark was right. Meanwhile, frustration with his father causes Lex to become enraged and attack a parking officer's car with a golf club. Forced to attend anger management class, Lex meets an interesting woman, Dr. Helen Bryce (recurring guest star Emmanuelle Vaugier - "My Guide to Becoming a Rock Star").

When Margaret is disappointed that no one but Todd can attend her family Thanksgiving dinner, Todd tries to convince his brother, Lawrence, to come home. Margaret's family helps her crack a case involving an injured bank teller and robbery.

Oliver tells Clark he must kill Davis, as Doomsday is a serious threat and must be stopped at all costs. However, Clark struggles with taking a human life, so the Green Arrow and his team decide to take matters into their own hands. Lois takes on Tess, but the fight takes a shocking turn. Meanwhile, Chloe gets caught in the middle of Oliver and Clark's battle over killing Davis.