Danno and McGarrett will soon be resuming their epic carguments as "Hawaii Five-0" returns for a seventh season.

"Hawaii Five-0" will be back on air in just a few days and, aside from seeing Danno (Scott Caan) and McGarrett (Alex O'Loughlin) bicker about everything under the sun, they and the rest of the team will be hunting down a nefarious serial killer who's targeting other serial killers.

Season 7's premiere episode, titled "Makaukau 'oe e Pa'ani" or "Ready to Play," will find the team on edge as the body of a serial killer is found in Five-0's headquarters. What makes the case more disturbing is the fact that the victim is a serial killer and was found with an ivory chess piece in his mouth. The body of another serial killer is soon discovered and it also has another chess piece, creating panic among the island's residents and tourists alike.

It's this murder spree that will allegedly bring criminal profiler Alicia Brown (Claire Forlani) to Hawaii. According to reports, Brown will find one victim literally between her sheets in episode 3, "He Moho Hou" or "New Player."

Viewers won't wait long to meet the Five-0 team's latest nemesis as the perp, dubbed the Chess-Piece Killer, will be introduced in the premiere episode.

Meanwhile, McGarrett will refuse to take things easy, even though he's still recovering from surgery, as he's determined to bring down this vigilante. Of course, this won't sit well with his partner.

Fans will recall that season 6's finale ended with Danno donating part of his liver to the gravely wounded Lieutenant Commander. While the experience has made the two friends closer than ever, it will reportedly lead to more arguments as Danno begs McGarrett to slow down. But "Hawaii Five-0" fans know that's unlikely to happen.

McGarrett's daredevil attitude isn't the only problem Danno will be facing this season. TVLine has reported that the hot-headed detective will also be dealing with his worst nightmare — Grace's first boyfriend. Showrunner Peter M. Lenkov won't say who will be playing the poor boy but admitted that "finding out who it is makes the ride so enjoyable."

"Hawaii Five-0" season 7 will be returning to CBS on Sept. 23 at 9 p.m.