Siren

A familiar superheroine from DC Comics lore arrives to Smallville in this terrific eleventh episode.

Chloe Sullivan has been working with Oliver Queen to locate Lex Luthor's facilities across the globe for his team of superheroes. However, Lex discovers that Chloe is working on this project. In response, he hires a swift, blond vigilante, known as the brunette Dinah Lance in her everyday life, to stop Chloe and anyone who has hired her to work on the project.

Convinced by Lex that Green Arrow is a terrorist, Dinah, in her "black canary"-like persona, tries to stop him. However, things change when Clark is able to convince her that she might not be on the right side. Meanwhile, Lois is able to see her former lover, Oliver, once again, and uncovers a startling secret about him. This causes Lois to re-evaluate several important factors in her life.

This episode is excellent for several reasons- the action scenes were superb, and even the slower moments were very pivotal and very well-acted. It was important that these slower scenes were well-played, since they played such a huge role in the development of several ongoing relationships in the show.