Mack heads home this week on "Agents of S.H.I.E.L.D." to reconnect with his brother, Ruben. His visit with family comes on the heels of losing agents Bobbi Morse and Lance Hunter, his closest friends at S.H.I.E.L.D.

Understandably, Mack (Henry Simmons) is taking the exit of Bobbi (Adrianne Palicki) and Hunter (Nick Blood) harder a little bit harder than his fellow agents. The reunion with his brother (played by "Friday Night Lights" alum Gaius Charles) seems to come at a perfect time.

"They're exploring a little bit of his life outside of S.H.I.E.L.D.," Simmons said of his character. "The opportunity where they explore how lives are affected, families are affected, by if someone is S.H.I.E.L.D. and they aren't allowed to tell, 'Hey, I'm in S.H.I.E.L.D.' They're not allowed to talk about that, and just how relationships are delicate and strained when you're in S.H.I.E.L.D. and you can't really tell anyone what you're doing. It's difficult."

A new enemy of Inhumans could put a further strain on Mack and Ruben's relationship. The two get caught in the crossfire when a radical group called The Watchdogs emerges with plans to eliminate the Inhumans.

To fill the void of Bobbi and Hunter, who were recently forced to deny their involvement with S.H.I.E.L.D. and walk away from the organization, could be the Secret Warriors. The team led by S.H.I.E.L.D. agent and Inhuman Daisy (Chloe Bennet) has stood on the sidelines for most of season three, but Coulson (Clark Gregg) could be calling them up for action soon.

"Stranger things have happened," executive producer Jeff Bell teased about the Secret Warriors next step.

The Secret Warriors, working under S.H.I.E.L.D. directive, so far includes Lincoln (Luke Campbell), Joey (Juan Pablo Raba) and Elena "Yo-Yo" Rodriguez (Natalia Cordova-Buckley), who chose not to stay with S.H.I.E.L.D. full-time.

"Being Inhuman and being a SHIELD agent, it's not just work, it's so personal because it's her blood, it's who she is," Bennet said. "I think having [Lincoln] on the team helps her open her eyes to seeing other aspects, because he's been an Inhuman longer and he's kind of not as sensitive to it or used to the criticism."

A new episode of "Agents of S.H.I.E.L.D." airs on Tuesday, March 29 at 9 p.m. on ABC.