Megan Hunt has been on a three-month leave after the death of her partner, Peter. He died saving her from the clutches of a serial killer. Things have changed since Megan has been away. Bud retired and Sam moved to Virginia to join the FBI. Ethan and Curtis are still around, as is big boss Kate. As far as the homicide detectives Megan will be working with, she ticks off Adam Lucas (Elyes Gabel) right away. That’s just because he doesn’t know her. The same can’t be said for his partner, Tommy Sullivan (Mark Valley). Megan is less-than-thrilled to see that this person from her past is back in her life.

While investigating the death of a man who drank himself to death in an alley, Megan uncovers a room with five additional dead bodies inside. They are all military combat vets who were being treated for PTSD. They also all had their spleen removed. Megan suggests the detectives check out other vets with similar builds to determine the next possible victim. In other news, a young woman named Charlotte is eager to impress the new Medical Legal Investigator. Megan welcomes her with open arms. Okay, she doesn’t do that at all. She’s brutal towards her. Charlotte quits almost immediately. Megan just isn’t ready for anyone to replace Peter.

Megan realizes the killer is most likely a surgeon—a plastic surgeon to be exact. He’s removing an organ nobody really needs only to kill his victims later. Megan’s expertise leads the cops to Dr. Harvey Wallace and his chief nurse, Yvonne Kurtz. The two of them met on a humanitarian mission in Afghanistan. Yvonne’s husband is a deceased vet. As for the good doctor, his suture work is found on all the victims. That’s not enough to hold the guy. As far as the malicious surgeries, the person performing them is seen with scary skeleton keychain which sits inside a makeshift OR.

Tommy convinces an ex-soldier with PTSD named Karl Simmons to act as bait to lure the killer into the open. Adam isn’t thrilled with this play. He pushes his partner for details on his relationship with Megan. Turns out they had a short, intense relationship 20 years ago. Tommy admits he’s the one who screwed things up. It looks like he made another mistake in the present day, as Karl is abducted right under his nose. On the bright side, Curtis does some fancy bug research to lead the cops to the killer’s location at the Port of Philadelphia. Tommy wants Megan to sit tight while they check it out. Yeah, that’s not gonna happen.