Agents of SHIELD, meet the Advanced Threat Containment Unit. ATCU, meet SHIELD. Now try to play nice, you two.

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Coulson's (Clark Gregg) search for the latest batch of Inhumans and similarly gifted individuals will be hampered when the ATCU arrives on the scene in season 3. Headed by Constance Zimmer's unnamed character, this new agency will have their own agenda for the Kree's human legacies. Unfortunately, it is still unknown whether the ATCU and SHIELD will be grudging friends or worst of enemies.

"That's to be determined," Elizabeth Henstridge (Simmons) said, according to E! Online. "But we're so excited to have Constance on the show, she's amazing. She's the perfect person to take on this role. But I can't say any more about it!"

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Given SHIELDs track record, it's probably safe to assume Coulson's team won't be making any new pals this fall. It's not that their an unlikable bunch, it's just that everyone they encounter seem to have the worst of intentions.

Do you think the ATCU will put Skye/Daisy's (Chloe Bennet) Secret Warriors project in jeopardy? You can find out when Agents of SHIELD returns to ABC on Sept. 29 at 9 p.m. ET.

Take a look back at season 2 with the video below.