Barney concocts a plan when his father (John Lithgow) arrives at the hotel; Ted thinks he is being framed when a wedding-related duty gets messed up.
Jax gets closer to the truth but there are still obstacles in his way.
After a mass murder at an Internet security company, evidence indicates that the person responsible is not a typical serial killer; Prentiss is required to complete recertification training.
The alien glyphs Coulson has been etching lead the team to several murder victims; lies and secrets come to a head.
Castle and Beckett find that Esposito has a personal connection to a suspected killer; Beckett connects with an attractive new detective.