One character's fate will hang in the balance on an upcoming episode of "Hawaii Five-0." 

On the 19th episode of the cop drama, the team will investigate a tip about a gun deal happening inside a parking garage.

A bomb will go off while they are investigating, imploding the whole structure—with some of the Five-0 team still inside. One of them will be badly injured, and oxygen will be in short supply. 

Also, on an upcoming episode, someone from the team will leave Hawaii and head to Afghanistan. 

Executive producer Peter Lenkov released the spoiler in a Valentine's Day tweet, right before the series' love-themed marathon aired last Friday. "Roses are red, Some can be yellow, One of #H50 is headed to Afghanistan, To save a fellow," Lenkov teased on Twitter. 

Viewers are now speculating if McGarrett (Alex O'Loughlin) or Catherine (Michelle Borth) is headed to Afghanistan, or if it's someone else entirely. While Catherine is no longer employed by the Navy, an upcoming look into Catherine's past has the potential for an Afghanistan flashback.

The episode, which will be the penultimate episode of this season, will also have a "big dramatic" romantic arc, according to TV Line.

Lenkov said the episode will include "some flashbacks to [Catherine's] stint in the military. You'll get to know her as a soldier, when she was actually in the Navy."

On the lastest episode of "Hawaii Five-0" before its brief hiatus, Danny (Scott Caan) went for a wild ride with McGarrett and an escaped convict.

In "Na Hala a Ka Makua" (Sins of the Father), convict Roy Parrish (Michael Madsen) deftly escapes incarceration.

Meanwhile, Danny has been called to the principal's office because of his daughter's minor transgressions. After his meeting with the principal, he and McGarrett are called to the scene of Parrish's escape. They plan to grab him and promptly put him back in jail, but Parrish pulls one over on them by hiding in the backseat of their car with a loaded gun.

The duo is then handcuffed together and forced to take Parrish to the place of his choosing. Parrish even uses Danny's daughter, Grace, to evade capture at a police checkpoint.

Meanwhile, Chin (Daniel Dae Kim) and Kono (Grace Park) visit Parrish's estranged daughter.

The rest of the Five-0 team search for Parrish, who they believe is out for violent revenge. But they're wrong—Parrish wants the witness who lied at his trial to recant his testimony and tell the truth about what really occurred.

McGarrett, Danny and Parrish are almost stopped by police, but ultimately outrun them after McGarrett decides to help Parrish after hearing his harrowing story. But when they reach the witness, they find him dead from a bullet to the head.

The three are then ambushed by gunfire, but are rescued by the Five-0 team. Parrish then escapes again, but this time it's to meet with his daughter. She thinks she is helping her dad by extending an invite to the FBI, but it turns out they're not real FBI agents. Parrish gets shot, as do the fake FBI agents.

In the next episode, "Pale 'la" (Buried Secrets), "A real estate agent is found dead inside the walls of one of his listings. Meanwhile, Danny's mother makes an unexpected visit and brings with her some shocking news."

Melanie Griffith will guest star on the upcoming episode, which will air Friday, Feb. 28 at 9 p.m. EST on CBS.