Newly engaged Seth and Summer both panic about the prospect of being married, but neither will break it off, despite the advice of their friends. Instead, they begin a complicated game of one-upmanship that almost leads them to Las Vegas for a wedding. Meanwhile, when Ryan's estranged biological father, Frank (recurring guest star KEVIN SORBO), who has been in prison for years, tries to reconcile with Ryan, Sandy remains dubious--and his instincts about Frank may just be correct. Also, rebellious Kaitlin's teacher orders her to be tutored by an insightful classmate, Will Tutt (recurring guest star musician CHRIS BROWN).