The Bobbi/Mac mystery will come to a boil as soon as Agents of SHIELD returns for the second half of season 2.

'Agents Of SHIELD' Season 2 Spoilers: 'Aftershocks' PHOTOS Hint At New Norm, A Visitor For Bakshi, A Fully Healed Mac

Skye (Chloe Bennet) and her Inhuman powers won't be the only mystery plaguing SHIELD during "Aftershocks" and "Who You Really Are." As Coulson (Clark Gregg) and Co. place their focus on Quake, Bobbi (Adrianne Palicki) and Mac (Henry Simmons) will continue with their secret - and potentially dangerous - side mission.

"Bobbi and Mack begin the next phase of a plan which seems to have grave repercussions for Coulson and his team, who are unaware that there's another mysterious force moving against them," ABC teased of the midseason premiere, adding that the follow up episode will see the duo "continue to hide their true mission from everyone close to them."

'Agents Of SHIELD' Season 2 Spoilers: How Will Series Handle Trip's Death? Agent's Mother To Appear

The cast of Agents of SHIELD is keeping mum regarding Mockingbird's little project, but Palicki gave a few cryptic hints while speaking to Screen Slam.

"It's just one of those things that, it's literally getting grayer and grayer and there's a lot of people who might feel very differently about certain characters, certain situations down the line," Palicki said of the Marvel Cinematic Universe.

Find out more when Agents of SHIELD returns to ABC on March 3 at 9 p.m. ET. Click the video below to see a preview for the series' midseason premiere.