Steve McGarrett and Catherine Rollins are shipping out to Afghanistan on Hawaii Five-0, and their mission will include some very difficult decisions for the Navy SEAL.

McGarrett & Danno Injured & Trapped? New Details For Explosive 'Hawaii Five-0' Episode

The couple will trade their island paradise for the Middle East's landlocked country during episode 21.

Executive producer Peter Lenkov teased the overseas trip in a Valentine's Day poem he crafted for his followers, tweeting, "Roses are red, Some can be yellow, One of #H50 is headed to Afghanistan, To save a fellow."

Scott Caan's Danny Williams Reappears On 'Hawaii Five-0'; Has 'Blood Brothers' Bonding Episode With McGarrett

While McGarrett (Alex O'Loughlin) and Rollins (Michelle Borth) were two obvious candidates for the mission based on their military backgrounds, it was initially unknown which soldier would be heading overseas. Thanks to TV Guide, it has now been confirmed that both the Navy SEAL and the former Navy intelligence officer will feature in the episode.

Titled "Makani" and set to air as the penultimate episode of season 4, TV Line states that the Afghanistan story line will feature flashbacks to Rollins' time in the armed forces, a "big, dramatic" romantic arc, and an injury for Steve.

Will the couple's romance come to an end after four years? Considering TV Guide has pointed out that McGarrett will need to make a "heartbreaking decision" during the trip, the Catherine and Steve relationship could be a dead duck.

Do you think McRoll will be kaput by the end of season 4? Tell us in the poll below!.

Hawaii Five-0 airs Fridays at 9 p.m. ET on CBS. Click the video below to see a preview for the series' next episode,
"Hōkū Welowelo (Fire In The Sky).”