The actor told Fancast that the season premiere will see his character Cal Lightman take part in a bank heist.
"We've just completed that [episode] and it's absolutely terrific," he said.
He added that the second episode will then feature a "bizarre, slightly psychotic" storyline involving a beauty pageant.
Roth also teased that a crooked cop played by Monique Curnen may become a "sexual interest" for Lightman.
"I think [the producers] are going to go down that road a little bit," he admitted.
"She's a very interesting character [and] Monique... is a terrific actress. She appears in the end of the second season, and then we bring her back."
He confirmed that Curnen's character may create tension between Lightman and Gillian (Kelli Williams).
He laughed: "I think there's trouble in the mix there."
Lie To Me's second season is currently airing on Fox. The third season is expected to air in November.