Every Major Clark and Lana Romantic Milestone in Smallville: Episode by Episode
The darkest chapter of the Clana relationship timeline unfolded throughout Season 6. Desperate for honesty, Lana accepted Lex Luthor's courtship, eventually agreeing to marry him under the false belief that she was pregnant. In the landmark episode Season 6, Episode 16 ("Promise"), Lana finally witnessed Clark using his heat vision and super speed while hiding inside a wine cellar. She realized Clark had spent years lying to keep her safe, not out of malice.
Despite this realization, Lionel Luthor coerced Lana into marrying Lex under threat of Clark's life. The toxic dynamic ended when Lana staged her own death in the Season 6 finale and fled to China. Clark rescued her in the Season 7 premiere ("Bizarro"), ushering in the healthiest, most stable phase of their relationship.
For roughly fifteen episodes, Clark and Lana lived together on the Kent farm. There were no longer secrets, kryptonite necklaces, or unreturned phone calls. Lana actively assisted the burgeoning Justice League, while Clark enjoyed a rare glimpse of domestic normalcy. However, the emotional toll of her marriage to Lex had hardened Lana, leading to an obsession with revenge that culminated in her kidnapping by Brainiac and her sudden departure at the close of Season 7 via a pre-recorded DVD farewell.