ABC's new pilot Marvel's S.H.I.E.L.D. has added two new agents to the fold, with Elizabeth Henstridge and Iain De Caestecker joining the cast.

The actors will portray Agent Gemma Simmons and Agent Leo Fitz, who both came up through the academy together and spend a majority of their time with each other. Don't expect any romance to come out of this duo, since their relationship is said to be on more of a sibling level, according to the casting breakdown from last month. Gemma is said to be a science expert, with Leo specializing in technology. Neither character is based on an existing Marvel character.

The actors join Ming-Na as Agent Melinda May and Clark Gregg, who reprises his Agent Coulson role from Marvel's The Avengers.

Joss Whedon will direct, and is writing the pilot script with Jed Whedon and Maurissa Tancharoen. The writers will also serve as executive producers alongside Jeph Loeb and Jeffrey Bell. It isn't known when production will begin on this highly-anticipated pilot.