'S.H.I.E.L.D.' Adds Elizabeth Henstridge, Iain De Caestecker To Cast

"S.H.I.E.L.D." has added two more agents. According to The Hollywood Reporter, Elizabeth Henstridge and Iain De Caestecker have joined the cast of Joss Whedon's ABC pilot.

Henstridge will play Agent Gemma Simmons and De Caestecker will play Agent Leo Fitz. The two characters spend all their time together and have a sibling-like relationship, according to the original casting breakdowns. Agent Simmons is a master in biology and chemistry while Agent Fitz is a technology and weapons guru.

Henstridge previously worked on a pilot for The CW and De Caestecker has numerous UK TV credits including "Coronation Street."

The duo join previously cast Ming-Na Wen and Clark Gregg. "ER" veteran Wen will play Agent Melinda May, a weapons expert and top pilot. Gregg will reprise his Agent Coulson role from "The Avengers" film. The show will take place in the Marvel cinematic universe, but don't expect it to be anchored on the "Avengers" characters.

"It's new characters. It needs to be its own thing," Whedon said. "It needs to be adjacent [to the MCU] but you don't want to do a show where you're constantly going, 'Iron Man just left, but he was totally here a minute ago.'"

Whedon is attached to direct the pilot. He'll co-write with his brother Jed and Jed's wife Maurissa Tancharoen, a duo that previously teamed for "Dr. Horrible."

Click through the slideshow below for more "S.H.I.E.L.D." casting suggestions.

Our Dream Cast For "S.H.I.E.L.D."