Once Upon A Time: Season 6, Episode 12

6 - 12: Murder Most Foul

Before Hook takes the next step in his relationship with Emma, he wants to make sure David sees him as more than just a pirate. So when David asks Hook to help him uncover the truth about his father's death, Hook agrees. Meanwhile, Regina works to acclimate Robin to life in Storybrooke, but soon discovers he has a dark side that makes the task much more complicated than she anticipated.