Clark discovers that Lana is missing and Tess Mercer may be responsible. Tess informs Clark of startling news concerning an old friend, then discovers startling news of her own at a secret LuthorCorp facility.
Desmond searches for a mysterious woman that can help them stop the island’s movements in time. Locke uncovers the person responsible for the attacks on the victims.
The team take on the case of a Special Education teacher who spits up blood and collapses in the middle of class. Meanwhile, Cameron finds herself taking on some of Cuddy’s duties, including dealing with House, and Foreman has to make a decision concerning Thirteen’s participation in the clinical trials.
Using the name Joe Foreman, Clark goes undercover to discover why Detective John Jones was shot. Meanwhile, Lana confronts Tess and reveals the truth about her involvement with Lex.
Hurley and Sayid are hunted down by the cops. Jack and Ben try to bring everyone together as a team. Kate recieves help from an old friend to hide the truth.
Several of the Oceanic Six survivors come to grips with their need to return to the island… on their own terms.
House and his team deal with a man living in constant pain. Meanwhile, Thirteen receives treatment by Foreman while taking part in his clinical trial on Huntington’s Disease, and Cuddy tries to balance her hospital duties with her new baby.
Three superheroes from the future travel to the past and join Clark in hopes that together they can defeat Brainiac, who has taken over Chloe’s body.
