Ep 4. Aqua

In Smallville season 5 episode 4, titled Aqua, Clark is saving people from a storm on the beach when he discovers Lois stranded in the ocean. He uses his powers to swim her back to shore, but they are both surprised when they are saved by a mysterious swimmer who appears to be able to breathe underwater.

Meanwhile, Lana returns to Smallville after her trip to Paris and has a strange encounter with a classmate, who has developed a fascination with water and exhibits some unusual behavior. Lana also has a tense reunion with Jason, who is hiding a secret about his past.

As Clark investigates the swimmer's identity, he discovers that he has ties to a secret organization that is experimenting with genetic modification, which has resulted in some dangerous side effects. Clark must race against time to stop the organization's latest experiment, a sea creature with deadly abilities that has escaped and is wreaking havoc on Smallville.

The episode also explores the theme of identity, as the characters grapple with revealing their true selves and dealing with the consequences of their actions. Clark struggles with his desire to reveal his powers to the world, while Lois deals with the aftermath of her recent stint in jail.

Overall, Smallville season 5 episode 4 provides a thrilling adventure for fans of the series, while offering deeper exploration of its themes and characters. With its mix of action, drama, and mystery, Aqua is a standout episode of the season.