Mary Lynn Rajskub, best known for her role as Chloe in 24, is to guest-star in the penultimate episode of the current season of Grey's Anatomy., which broke the story, says Rajskub and Patrick Fischler (Phil in Lost) will play a couple on their third honeymoon who arrive at Seattle Grace complaining of mysterious symptoms.

The episode will air on US television on May 10, with the season finale airing on May 17.