Meredith (Ellen Pompeo) and Derek (Patrick Dempsey) may have rekindled their relationship in last week’s episode of “Grey’s Anatomy” Season 11, but it looks like the former Grey Sloan doctor will be butting heads with someone new in episode 18 of the hit ABC series. According to the promo video for the forthcoming installment titled “When I Grow Up,” Derek and his sister Amelia (Caterina Scorsone) will be experiencing a little bit of sibling rivalry following Derek’s return from D.C.

Could this Shepard Showdown end in disaster? Sure seems that way. When Derek accepted his presidential gig on the East Coast, Amelia was promoted to her brother’s position as Head of Neurosurgery at the Seattle-based hospital. But now that Derek is back will he be vying for his former job?

Although Derek claimed in the trailer for episode 18 that he had no problem working for his sister, Amelia isn’t completely convinced. “You don’t do second place,” she says to her brother who promised that he wasn’t going to try and steal back his job. “I know you, Derek,” she rebuts.

That she does. In episode 7, Derek showed his true colors after he threw his sister under the bus in an attempt to snake back his job. But after realizing what he had done, Derek had a change of heart and owned up to his petty ways, explaining that Amelia was the best there was for the role of Head of Neuro. Although Amelia was appreciative of her brother’s retract, she won’t forget that he tried to get her fired due to her dark past.

Scorsone explained to TVLine in November that Derek’s betrayal would “fundamentally change the way Amelia sees him, and the way she sees the dynamic of their relationship." And it looks like Scorsones’ character is owning up to that statement in episode 18.

But that’s not all we know about the upcoming installment. According to reports, fans will be introduced to a new, tall, dark and handsome hunk in “When I Grow Up.” It was revealed that “True Blood” actor Kevin Alejandro would be taking on the role of Jack Pruitt, a “strong and rugged” police captain who catches the eyes of the scrub-donning dames of Grey Sloan. But it will be Callie (Sara Ramirez) who is granted the opportunity to operate on Jack’s leg. Could this be the start of a budding romance?

Jack will make his way to Grey Sloan after two injured cops (who also happen to be brothers) get dragged in to the emergency room. The “blood bath” of a scene will interrupt a school field trip that’s taking place at the hospital.

“Grey’s Anatomy” will air episode 18, “When I Grow Up,” on Thursday, April 2, at 8 p.m. EDT on ABC.