Barney meets his father; the gang points out things each of them should know but never learned.

Barney tries to make his life seem more exciting as he bonds with his father (John Lithgow); Robin encounters a guy she likes.

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.

With only a half an hour left before the wedding, Robin and Barney panic; Lily and Marshall rewrite their wedding vows.

Dexter investigates the Trinity Killer; Debra blames herself; Rita realizes she knows little about her husband.

Vigilant neighbors, an inability to drive and a fascination with Trinity's technique interrupt Dexter's routines.

Despite the appearance of a perfect life, Dexter struggles to settle into his domestic situation.

Dexter questions his father's code and seeks answers on a road trip with Trinity; Debra discovers she has been blinded to the truth.

With Rita and the children out of town, Dexter gets time to himself.

Dexter works to stay ahead of the Trinity investigation; an unexpected source offers advice on the friction between Rita and Dexter.

Dexter strikes a balance between family, work and his secret life; Debra expresses a renewed interest in her father's past.

Dexter must rethink the Trinity case when a boy goes missing; Cody defends one of Dexter's lies; Debra's discovery causes problems for Quinn.

While investigating slayings with Agent Lundy, Dexter misplaces crucial evidence that could expose him.

Miami Metro is close to discovering Trinity's identity; Dexter takes drastic actions to buy time; Arthur begins to investigate Kyle Butler.

Arthur warns Dexter to back off; Rita and Dexter plan a honeymoon; Debra unearths a hidden truth.

Dexter uses Thanksgiving to get a closer look at Trinity's life; Rita prepares dinner for a packed house; Batista gets closure on an old case; Debra has an idea about her shooter.