Haley (Bethany Joy Galeotti) receives news of a possible tragedy. Dan's (Paul Johansson) search for Nathan (James Lafferty) leads him back to his dark past. Clay (Robert Buckley) has a breakthrough in his treatment. Brooke (Sophia Bush) and Julian (Austin Nichols) deal with Xavier (guest star Devin McGee). Chase's (Stephen Colletti) concern for Chuck (guest star Michael May) pushes him to his limits.