What's up with Lana? Lana's long lost great-uncle Dexter summons Lana to his prison hospital bedside. He tells her he didn't kill his wife, Lana's great-aunt Louise, although Deputy Billy Tate found him with the body and gun in hand. He wants Lana and Louise's family to learn the truth. Great-uncle Dexter claims the drifter killed his wife. Lana sees that an old newspaper drawing of the man looks exactly like Clark. Lana tells Clark the drifter could've been his father or grandfather.

What's up with Clark? The drawing of the drifter shows a medallion around his neck with an etched Kryptonian symbol Clark remembers from the cave drawings. Jonathan and Clark find the drawing on the cave wall. Clark touches the wall. It opens. As he reaches inside, he has flashbacks of the drifter and he finds the medallion. Later Clark realizes that the medallion is a diary of Jor-El's time in Smallville.

Through various flashbacks, Clark sees Jor-El and his life in Smallville, calling himself "Joe." Jor-El's father had sent him to earth for a lesson. While in Smallville "Joe," met and loved Lana's great-aunt Louise who was married to Dexter at the time. They met when "Joe" saved Louise from an armed robbery attempt by would-be burglar Lachlan Luthor, Lex's grandfather. As their relationship grew, "Joe" told Louise he had to leave Smallville to return home. Louise wanted to accompany him. "Joe" tried to explain that it wouldn't be possible. He even demonstrates his flying abilities, elevating Louise, so she would understand why she couldn't return home with him. On their last night together, Lachlan Luthor found them together in the barn, shooting "Joe" many times. "Joe" was unhurt, but one stray bullet caught Louise, who died in "Joe's" arms.

While investigating the circumstances of Louise's death, Lana and Clark find out that present Mayor William Tate was Deputy Billy Tate at the time. He released Lachlan Luthor from jail on the day Louise was shot dead. Lana and Clark visit Mayor Tate to ask about Lachlan. Clark's flashback leads him to discover that Tate was also in love with Louise. Clark encourages the Sheriff to investigate Mayor Tate's connection with Louise's murder. Clark believes Tate made a deal to drop charges on Lachlan on the attempted burglary if he'd kill the drifter "Joe." Tate could then pin the murder on Dexter.

Another flashback reveals that Jonathan's father Hiram Kent believed that "Joe" was innocent and tried to help him escape.

What's up with Lex? Chloe questions Lex about his grandfather Lachlan Luthor. He has no answers. Lex later confronts Lionel with the story of Lachlan's attempted crime and Lionel's story of his grandfather's heritage from Scottish nobility. Lionel admits he fabricated the lineage of his parent's to erase his past of poverty. In reality, grandfather Lachlan and his wife died in a tenement fire in the slums.

Lex has an investigator probe into his grandparent's deaths. Lex tells Lionel that the fire in the tenement where his grandparents died was caused by an explosion originating from the family's apartment. There were traces of ammonium nitrate found. (Although it wasn't mentioned in the episode, ammonium nitrate is an ingredient of fertilizers). Lex is curious why Lionel never sought revenge. Lex tells Lionel they need to find out who was responsible for the murder of Lionel's parents, for justice.

How it ends: Clark impersonates "Joe," slicking back his hair and wearing Grandpa Hiram's old leather bomber jacket along with the medallion. He confronts Mayor Tate, telling him to confess to Louise's murder. Clark (as "Joe") dodges bullets as Tate tries to kill him. The Mayor is so distraught, that when Clark disappears and the Sheriff arrives, Tate mutters a confession, "Lachlan was supposed to kill the drifter. I never meant to kill Louise. I loved her."

Lana visits her great-uncle Dexter in the prison hospital. He's finding it hard to believe that Tate really was behind Louise's death and let him take the rap serving the past 42 years in prison.

Back in the cave, Clark has a flashback of "Joe" placing the medallion back into the cave wall. Clark's grandfather Hiram found him there, telling "Joe" "If there is ever anything you need, you know where to find me." Clark tells Jonathan he doesn't think he and Jonathan found him by accident. They were chosen as Clark's adoptive parents.