As with nearly all episodes this year on "Hawaii Five-0," the upcoming installment is slated to add to the season-long plot, as well as pack in a couple of cases for the week. Episode 12 also includes a very special guest appearance by Carol Burnett.

The episode is titled "Ua Ola Loko I Ke Aloha," which translates to "Love Gives Life Within," according to TV Guide.

While Steve McGarrett (Alex O'Loughlin) has faced many challenges over the course of this season, none have been quite as pressing as when his aunt shows up on the island. Fans of the show might be even more thrilled to find out the character is played by guest star Burnett.

According to Spoilers Guide, Burnett shows up on the island to get her nephew's help on a very special quest. This is not just some random mission that requires his unique skills in law enforcement, but a specific request from his aunt for something that is quite personal to her.

Of course, McGarrett has no other choice but to help her, if for nothing beyond his loyal sense of duty. Fans might just get to see a comical side to the series here.

Elsewhere in the episode, the island hides a few Japanese bombs, dating back to the days of World War II. The explosives were left hidden, but remain active. When the Five-0 unit shows up to collect them, however, they turn out to be missing.

The real meat of the episode follows the team as they investigate the stolen devices. The case could provide a special key to some unanswered questions in their season-long investigation involving Gabriel.

Either way, McGarrett will be a little pre-occupied with his aunt, so the rest of the team members have to find their own way to solve the mystery.

Episode 12 will air on broadcast network CBS this Friday, Jan. 15 at 9 p.m. ET. Fans can watch a preview of the episode below.