S7, E14: Nathan tries to keep Haley calm after Taylor (guest star LINDSEY McKEON - Supernatural, Veronica Mars, IQ-145) shows up at their house with Quinn's ex-husband, David (recurring guest star SCOTT HOLROYD), in tow. Clay gets a chance to prove his commitment to Quinn by helping her through a dinner with David and Haley. Meanwhile, Julian sticks up for Alex (recurring guest star JANA KRAMER) on the set of their movie, and Brooke leans on Alexander (recurring guest star MITCH RYAN - upcoming The Pacific) to ease her heartache.