If you're an Agent of SHIELD, you probably want to keep your family as far from your work as possible. For Mack, this will become exceedingly difficult once his brother drops into the "Watchdogs" storyline.

Coulson's (Clark Gregg) team live secretive and dangerous lives, ones which keep them away from their relatives for long periods of time. Marriage is generally out of the question unless your soul mate works in the same field, and only Daisy (Chloe Bennet) and May (Ming-Na Wen) have received any type of storyline with their families. As the public continues to reel from the Inhuman outbreak, Mack (Henry Simmons) and his brother will find themselves caught in the midst of the panic.

"When a radical group called The Watchdogs emerges with plans to eliminate the Inhumans, Agent Mack and his brother become caught in the crossfire," ABC teased. "Meanwhile, Simmons discovers a powerful chemical compound that could alter the future for the Inhumans."

Gaius Charles will take on the role of Ruben Mackenzie on March 29. Little is known about the newbie - is he in league with the Watchdogs? Fighting against them? Is he somehow affiliated with SHIELD? - but new photos seem to indicate that he will have at least be standing side-by-side with Mack for some of the time.

From the looks of it, the Watchdogs will pose a formidable threat. Militaristic with a high-tech base of operations and plenty of firepower, the trio pictured below would probably get along great with Lash if they weren't so virulently opposed to his DNA. Getting their butts kicked by Daisy will certainly bruise their ego.

In the meantime, viewers can catch the SHIELD heroes in tonight's "Inside Man." Coulson and General Talbot (Adrian Pasder) will have to put aside their differences in order to take on a worldwide symposium on Inhumans. A traitor will be revealed, and betrayal will propel the story into "Parting Shot." Bobbi (Adrianne Palicki) and Hunter (Nick Blood) will be hot on Malick's (Powers Booth) trail when they head to Russia, but an assassination plan will throw a wrench in their mission.

Catch Agents of SHIELD Tuesdays at 9 p.m. ET on ABC. Check out a preview below.

Tags: Marvel's Agents of S.H.I.E.L.D. television ABC Marvel