Regina (Lana Parrilla) helps Robin (guest star Sean Maguire) navigate his new life in Storybrooke, while David (Josh Dallas) seeks help from Hook (Colin O'Donoghue) to learn the truth behind his father's death on the upcoming episode of "Once Upon a Time" season 6.

Titled "Murder Most Foul," next week's episode will see Hook go out of his way to prove that he deserves to be with Emma. According to the official synopsis, Hook is determined to take his relationship with Emma to the next level. However, he wants to be sure that David sees him as more than just an ordinary pirate first. When David asks help from Hook to uncover his father's death, the latter immediately agrees.

Elsewhere, Regina helps Robin adjust to life in Storybrooke. She soon realizes that he has a dark side which makes the task more complex than expected. Also guest starring in this episode is Eion Bailey as Pinocchio also known as August.

Series co-creator Eddy Kitsis recently spoke with TV Line and teased that the next episode will focus on David a.k.a. Charming and Hook. "Episode 12 is going to be the further adventures of one of my favorite bromances in the world, Hook and Charming, finding out who killed David's dad." Co-creator Adam Horowitz was also present during the interview and he confirmed that more details about David's father will be revealed "by Easter."

Sunday's midseason premiere saw the Robin make a grand return to Storybrooke. Thanks to August, Regina and Emma finally escaped the wish realm — bringing back Robin as well. While Regina and Emma were away, Belle (Emilie de Ravin) and Rumple (Robert Carlyle) learned how angry Gideon (Giles Matthey) was when he discovered that they let him be caught by the Black Fairy.

The 6th season of "Once Upon a Time" airs every Sunday night at 8 p.m. EST on ABC.