'Hawaii Five-0' Season 4 Episode 7 Spoilers: Team Gets Tasked with Diaper Duty [Video]

Last week's "Hawaii Five-0" celebrated Halloween by featuring the team running into some tropical "zombies."

In "Kapouli La" (Broken), Max (Masi Oka) attends a beach party with Sabrina (Rumer Willis), but the party gets interrupted by a man who attacks party guests, which leads Max to believe the man is a zombie. Meanwhile, Catherine (Michelle Borth) is trying to cope with Bill's death, as well as with leaving the Navy. McGarrett (Alex O' Loughlin) helps her cope by offering a new perspective on the situation.

Chin (Daniel Dae Kim) shows up at the crime scene. Max gave CPR to the deranged attacker, causing him to also be infected with the strange, zombie-like ailment.

It's then revealed that the "zombie" is a doctor who works at the hospital to which he was admitted. It's discovered that both the man and Max had been exposed to Scopolamine, a medicine used (sparingly) to treat motion sickness and postoperative nausea and vomiting. Scopolamine can render a victim unconscious for 24 hours, and in large doses can cause respiratory failure and death. Criminals sometimes use it to rob their victims.

McGarrett and Danny go to a party where the victim/attacker had been. They find out that someone kidnapped the victim to get access to the morgue, and took a dead woman's head with him. They learn that the woman had been abducted before, and was missing for 30 days. She died a year later in a car crash. They search the deceased woman's house and learn that she was under surveillance.

It's later discovered that the two victims-- the man at the party and the headless deceased woman-- had been experimented on; someone is conducting experiments on humans, and the victims are being used as lab rats.

After questioning the victims, they come up with a suspect, a man by the name of Dr. Ellery. The team eventually find him, but he ends up being killed by one of his own "lab rats." Max also recovers from the ordeal. 

The next episode, "Ua Nalohia" (In Deep), will focus on the murder of a government agent-- as well as a little bundle of joy.

The synopsis reads: "Five-0 is tasked with babysitting Mary's newly adopted baby, even as they investigate the murder of an undercover ATF agent. "

Kono (Grace Park) will also return to the team in an upcoming episode. Showrunner Peter M. Lenkov told TVLine that she will be back "midseason."

Watch the promo for "Ua Nalohia," which airs Friday, November 8 at 9 p.m. on CBS.