Smallville :

Clark is stunned to see his father's ghost at the graveyard but becomes even more confused when Jonathan tells him to kill Lionel. Jonathan appears again, and gives Martha the same message.

Meanwhile, after Lex develops a vaccine for Fine's deadly virus, Fine intervenes and injects Lex with the vaccine, causing a shocking reaction. Clark realizes Jonathan is not who he claims to be, and Jor-El takes possession of Lionel so that the intruder can be destroyed.